Seeking Out With The Old And in With The New Considerations

[uncndl1]

We bought this old farm house 2 years ago with a now 38 year old HS Tarm OT35 combination wood and oil boiler. Previous owners used mainly wood since boiler was new but we’ve using oil since we’re not home much. Average oil consumed past 2 years is 590 gallons. I know the old steel and cast iron fittings aren’t going to last forever so wanted input into what to replace with and how to find reputable dealers in our zip code area 12020.
Currently leaning towards a new oil or pellet system. I’m thinking with a storage tank the system won’t need to be as large as our current system.
Anyone using Evoworld, Froling P4, Effecta Komplete III, EcoBoiler, or WoodMaster on this site?

 

[JohnDolz]

Good stuff. I do not own an Effecta Pellet Boiler but I do own one of their Log Boilers. I can tell you that I feel it is a great product and great company. NPAlaska, who posts here. runs an Effecta Pellet Burner on his Effecta Logboiler. Maybe he will see this and jump in to give you his perspective. Good luck!

 

[peakbagger]

Looks like you have a lot of choices before you pull the trigger.

First thing to consider is energy efficiency upgrades to the house. Since the prior owner was heating mostly with wood, they may not have been as concerned with how much wood they used. It would be worth checking with the local utility to see if they have subsidized energy audits and possibly upgrades.

The next thing is to determine if your mortgage company will allow a pellet boiler to be your primary heating sources. In the past most mortgage companies required conventional backup like propane, gas, oil or electric. Pellets were lumped in with wood.

Realistically there are no good dual fuel heating sources, the old tarm you have is a compromise, both the wood and oil sides are going to be less efficient than separate units. One major reason why they were popular is that they were rated to go into one flue. Many homes didn't have extras flues so they didn't have the choice of two separate heating sources.

How tight is your budget?. A whole house pellet boiler install is in the 15 to 20 K range. A high efficiency low mass cold start oil boiler like a System 2000 is going to cost half that installed. A cold start cuts standby losses substantially as it doesn't remain hot when there is no heating demand. Economically oil is on par with pellets price wise, sure the oil market could go wacko again but most intermediate term predictions are US shale oil production and decreasing demand for transportation fuels is going to hold prices somewhat stable. The dirty secret is delivered pellet pricing is directly linked to oil costs. It takes a lot of fuel to convert low grade wood in woods to a pellet plant and lot of electricity and fuel into pellets and then even more oil to ship them. Unless you want to pay a premium for "green" I expect at best its a wash on ongoing price.

How hands on do you want to be, pellet boilers are going to require a bit more work than an oil boiler. Higher end units required less but the ash needs to be emptied on occasion. Fuel quality can also give you problems. It seems to have gotten better over the years but unlike heating oil, pellets quality and characteristics tend to change by supplier and fuel source. On occasion you may get a load of pellets and they just plain will not want to run well. In that case either you or a paid service tech needs to troubleshoot.

Another issue, few folks don't want to deal with the tons of pellets needed for a primary heating source. In some areas there are firms that do bulk delivery but its pretty slim with little or no competition. They will need to visit more often so how accessible is your home to good roads?

Stick wood can be less expensive than oil or pellets as you potentially are cutting out the middlemen. The key thing is you have to place no value on your labor. Sure you might be able to buy bulk wood from a logger for cheap, but that wood needs to be cut and split stacked and seasoned for 2 years. If you like the exercise or the feeling of self reliance or if you are doing small scale timber management on the farm and you don't have to buy it then consider wood. Based on the past oil consumption and a rough rule of thumb of 1 cord is equivalent to a 100 gallons of heating oil, you are looking at needed to source and process and store 12 cords of wood and let it sit for 2 years and then commit to an additional 6 cords a year. That's a lot of work for some folks. Its going to take up a lot of your spare time. If you like doing it fine but many would rather write a check.

You asked about storage. It only makes sense with stick wood as a wood boiler is batch heater best run full bore for several hours at a time until the storage is full and then shut down until the storage gets low. Pellet boilers are continuous heaters, they don't benefit from large storage as they meter out the fuel continuously and only supply heat when the thermostats call for it. Storage for a house your size will be quite large and getting it in place may be challenge as the old prpane tanks many people use do not fit in very readily through interior doors or even a bulkhead. There is non pressurized solution to get around that but in either case its not cheap and the initial cost is in the 15 to 25 K range.

What may be the best option for you is get a wood stove for interior space heating up on the main floor. If you have a good spare chimney the install cost can be a lot lower. Its good way to see if you want to really hassle with wood in the long run. Alternative get a pellet stove which is somewhat less work prepping the fuel supply but depending on your pellet source it may require frequent cleaning. The wood stove is nice as if you lose power for an extended period its the only heating source that does not need electric power. Assuming you have some wood set aside

IMHO, My approach would be , have an energy audit done ASAP, spend money to reduce energy usage, have the Tarm oil side tuned up and serviced. Line up a firm to swap out the Tarm with a System 2000, get an estimate and sit on it unless the service shows that the existing Tarm is ready to fail. Then buy a chainsaw and splitting maul and spend the winter getting a firewood pile. If in the spring you think you want to go wood, buy a wood stove.

 

[uncndl1]

Looks like you have a lot of choices before you pull the trigger.

First thing to consider is energy efficiency upgrades to the house. Since the prior owner was heating mostly with wood, they may not have been as concerned with how much wood they used. It would be worth checking with the local utility to see if they have subsidized energy audits and possibly upgrades.

The next thing is to determine if your mortgage company will allow a pellet boiler to be your primary heating sources. In the past most mortgage companies required conventional backup like propane, gas, oil or electric. Pellets were lumped in with wood.

Realistically there are no good dual fuel heating sources, the old tarm you have is a compromise, both the wood and oil sides are going to be less efficient than separate units. One major reason why they were popular is that they were rated to go into one flue. Many homes didn't have extras flues so they didn't have the choice of two separate heating sources.

How tight is your budget?. A whole house pellet boiler install is in the 15 to 20 K range. A high efficiency low mass cold start oil boiler like a System 2000 is going to cost half that installed. A cold start cuts standby losses substantially as it doesn't remain hot when there is no heating demand. Economically oil is on par with pellets price wise, sure the oil market could go wacko again but most intermediate term predictions are US shale oil production and decreasing demand for transportation fuels is going to hold prices somewhat stable. The dirty secret is delivered pellet pricing is directly linked to oil costs. It takes a lot of fuel to convert low grade wood in woods to a pellet plant and lot of electricity and fuel into pellets and then even more oil to ship them. Unless you want to pay a premium for "green" I expect at best its a wash on ongoing price.

How hands on do you want to be, pellet boilers are going to require a bit more work than an oil boiler. Higher end units required less but the ash needs to be emptied on occasion. Fuel quality can also give you problems. It seems to have gotten better over the years but unlike heating oil, pellets quality and characteristics tend to change by supplier and fuel source. On occasion you may get a load of pellets and they just plain will not want to run well. In that case either you or a paid service tech needs to troubleshoot.

Another issue, few folks don't want to deal with the tons of pellets needed for a primary heating source. In some areas there are firms that do bulk delivery but its pretty slim with little or no competition. They will need to visit more often so how accessible is your home to good roads?

Stick wood can be less expensive than oil or pellets as you potentially are cutting out the middlemen. The key thing is you have to place no value on your labor. Sure you might be able to buy bulk wood from a logger for cheap, but that wood needs to be cut and split stacked and seasoned for 2 years. If you like the exercise or the feeling of self reliance or if you are doing small scale timber management on the farm and you don't have to buy it then consider wood. Based on the past oil consumption and a rough rule of thumb of 1 cord is equivalent to a 100 gallons of heating oil, you are looking at needed to source and process and store 12 cords of wood and let it sit for 2 years and then commit to an additional 6 cords a year. That's a lot of work for some folks. Its going to take up a lot of your spare time. If you like doing it fine but many would rather write a check.

You asked about storage. It only makes sense with stick wood as a wood boiler is batch heater best run full bore for several hours at a time until the storage is full and then shut down until the storage gets low. Pellet boilers are continuous heaters, they don't benefit from large storage as they meter out the fuel continuously and only supply heat when the thermostats call for it. Storage for a house your size will be quite large and getting it in place may be challenge as the old prpane tanks many people use do not fit in very readily through interior doors or even a bulkhead. There is non pressurized solution to get around that but in either case its not cheap and the initial cost is in the 15 to 25 K range.

What may be the best option for you is get a wood stove for interior space heating up on the main floor. If you have a good spare chimney the install cost can be a lot lower. Its good way to see if you want to really hassle with wood in the long run. Alternative get a pellet stove which is somewhat less work prepping the fuel supply but depending on your pellet source it may require frequent cleaning. The wood stove is nice as if you lose power for an extended period its the only heating source that does not need electric power. Assuming you have some wood set aside

IMHO, My approach would be , have an energy audit done ASAP, spend money to reduce energy usage, have the Tarm oil side tuned up and serviced. Line up a firm to swap out the Tarm with a System 2000, get an estimate and sit on it unless the service shows that the existing Tarm is ready to fail. Then buy a chainsaw and splitting maul and spend the winter getting a firewood pile. If in the spring you think you want to go wood, buy a wood stove.

Thanks so much for a comprehensive analysis!
Lots to think about as mentioned above.
I thought about a wood stove on the main floor.
Would need a chimney Installed for that but no matter what we do money will be spent.
The energy audit is a great first step, thank you.
The current system is cleaned regularly by us and filter with nozzle changed yearly.
Last analysis came in at 78% by the oil company so know there's room for improvement.
We have a very old electric water heater and our monthly electric bill runs $100-135 each month.
Was thinking since we're already heating a boiler maybe our DHW could come from the same system.
The more reading I do is helpful but all your insight is appreciated too.
I see that Woodmaster has an add on pellet option called Renovator that I'm curious about, wondering if I could modify my wood burner side with that, instead of modifying the oil side.
Not afraid with the maintenance and work involved with burning wood but thinking a hopper in the basement that holds 4 tons is attractive.
I'll keep you informed as to follow up.
Thanks again.

 

[maple1]

DHW only runs us about $25/mo on 0.18/kwh electricity.

 

[leon]

We bought this old farm house 2 years ago with a now 38 year old HS Tarm OT35 combination wood and oil boiler. Previous owners used mainly wood since boiler was new but we’ve using oil since we’re not home much. Average oil consumed past 2 years is 590 gallons. I know the old steel and cast iron fittings aren’t going to last forever so wanted input into what to replace with and how to find reputable dealers in our zip code area 12020.
Currently leaning towards a new oil or pellet system. I’m thinking with a storage tank the system won’t need to be as large as our current system.
Anyone using Evoworld, Froling P4, Effecta Komplete III, EcoBoiler, or WoodMaster on this site?

======================================================================================================


You not burning a lot of oil.

Before you spend any of your hard earned money I would like you to purchase two paperbacks "Pumping Away" and Classic Hydronics.
If you buy them from (broken link removed) you buy them directly from the author or you can order them from AMAZON or Barnes & Noble.

These 2 books were written by Dan Holohan. Mr. Holohan grew up in the plumbing business being a plumbers helper, technical sales rep for B+G and Taco and a plumbing and heating trouble shooter on Long Island.

Mr. Holohan makes his reading fun and informative for the experienced plumber and the lay person and he talks about the history of plumbing and heating and the Dead Men who were responsible for the plumbing and heating systems we use today as well as the physics involved in plumbing for heating and cooling and what is needed as well as great ways to avoid crawling around on you hands and knees to bleed radiators by power purging them when you fill them with cold water by placing boiler drains in each cool water return loop before the boiler sump.

Save your money, you do not need a new boiler.

Have the oil burner serviced and then clean the boiler tubes with the brushes that came with the boiler.


If I remember your Tarm correctly you need to remove the steam chest cover to remove the lid that seals the vertical boiler tubes to brush them out to clean them.

Cleaning the boiler flue pipe to the ash door in the chimney should also be done too.

NO, NO. NO, you do not have to worry about the boiler or the steel pipe fittings until they develop a leak so no worries there at all. I have steel pipe fittings and they are very old and do not leak so no worries there.

A few simple parts will make your boiler last much, much longer and prevent needless expense.

1. back flow preventer
2. Low Water Cut Off switch wired in series as the first boiler control before the triple aquastat.
3. Boiler Bypass valve. The boiler bypass valve saves fuel by using the water in the heating loop and recirculating it and mixing it with the hot water in the steam chest.
4.
The B+G RB122-E is what I would recommend for a low water cut off. Doing it in this manner shuts the power off to the boiler in the event of a low water condition and prevents the boiler from firing if there is no water in the steam chest and also preventing an explosion from water contacting the dry boiler walls.

5. Drain the boiler off completely and flush it out and then add a can of Fernox after the backflow preventor is installed to protect the boilers wet parts.


You may want to consider replacing the triple aquastat and L6006A with a new one.

I have the Honeywell L8124L1011 horizontal triple aquastat and the RB-122-E Low Water Cut Off and a Honeywell L6006A in my coal stoker boiler and they are excellent units.

These mechanical boiler controls that are not affected by high voltage spikes and low voltage conditions which will destroy digital boiler controls.

I had 2 Hydrolevel 3250 Plus triple aquastats and they were both faulty with bad computers and the low water cut off controls did not work on either unit and I replaced them with the Honeywell L8124L1011 Triple Aquastat and the Mcdonnel & Miller Bulldog RB-122-E Low Water Cut Off.

There is no need to spend a huge amount of money to replace your current boiler when all you need is new control parts and installing the circulator above the steam chest pulling water from the large steam chest tapping to pump away from the boiler.

All you need is a little work and a few new parts and you do not have to spend a huge amount of money to do this and you can leave your oil boiler to run on summer temperatures of 160 high 140 low with a 10 degree differential on the triple aquaststat and leave the L6006A at 190 with a 15 degree differential for the dump zone temperature.

Spoil yourself and your spouse with a vacation with the money you will save by doing simple repairs with new parts or hiring a plumber to do them and you will save many thousands of dollars you can spend on a hobby or a dream vacation.



Save Your Money and do the simple upgrades and repairs.that is all you need to do.

 

[maple1]

I would not drain & flush a boiler that has been in service that long, I don't think. Likely wouldn't touch anything on it at all. Any dirt inside should have long ago settled out into spots where it will harmlessly rest until the end of the boilers time. And all of the oxygen in the water should be long gone and the boiler & systems innards coated with naturally forming stuff that does that inside a closed boiler system. Post 3 above pretty well nails what I would advise. Around here you would pay more to heat with pellets than oil I think.

 

[leon]

Have you ever cleaned the vertical heat exchanger tubes in your Tarm boiler? If not It they need to be cleaned as they will have soot and fine ash on the sides affecting the rate of heat exchange in the boilers combustion area.


Adding a boiler bypass loop and an insulated horizontal storage tank would be one of the first things I would do after installing a low water cut off and back flow preventer and cleaning the vertical boiler tubes would be next as you will have much more thermal mass to use to heat the home using a very small amount of oil and it would not cycle as often as your hot water loop will only take so much heat from the boiler and the storage tank if you plumb them in series.

 

[peakbagger]

I am biased, I know of two folks over the years with similar vintage Tarms that had to replace them due to dome gasket leaks. I think in both cases they probably could have been repaired/rebuilt but the owners needed heat. I think one of them mentioned he contacted the folks in Lyme and they claimed they were told that they were approaching the reasonable life of that model. I dont know what wears out on them.

No matter what you do with the tarm, its not going to have great annual fuel efficiency. The current approach to modern oil boilers are low mass triple pass heat exchanger set up as cold start unit. This eliminates the standby loss of having a poorly insulated boiler full of hot water 24/7 in case there is demand for oil. I figure a gallon of fuel oil per day for standby loss. The stated oils usage is quite lower that I would have expected.

If you just want to stick with what you have, the best investment is an outdoor reset controller and possibly a new gun. The reset controller adjusts the boiler water temperature based on outdoor temperature. The age may mean it may not have a retention head burner, switching over a to retention head will reduce oil usage a bit.

 

[uncndl1]

Just read all the additional posts and appreciate all the information and advice. I’d like to know more about hydronic and plumbing so will look at those books. The operating instructions are somewhat vague and say to use a scraper through the wood loading door and ash door to clean the flat surfaces. The long handled brush is used to get down between the baffles that are visible through the clean out door. Nothing mentioned about removing any panels except for chimney cleaning which is done yearly when the oil filter and nozzle are changed out. I do clean what is accessible through the two doors every two months. The flue exit from boiler is cleaned each year but haven’t removed any panels. Will have to look into the other suggestions once winter is over and have read some more. The circulators are on the return lines from radiators and baseboards close to bottom inlet
(2 zones). I do know there is no mixing valve as recommended in directions and our hot water heater is in series with the internal boiler coils for hot water.
Lots of reading to do and once again appreciate all the pointers which will be looked into. I will save the money for now which is what I was hoping as we like to pay cash for our repairs and improvements. The cold start Energy Kinetics system sounds interesting for the future if a changeout is needed.


Sent from my iPad using Tapatalk

 

[TimCroft]

We bought this old farm house 2 years ago with a now 38 year old HS Tarm OT35 combination wood and oil boiler. Previous owners used mainly wood since boiler was new but we’ve using oil since we’re not home much. Average oil consumed past 2 years is 590 gallons. I know the old steel and cast iron fittings aren’t going to last forever so wanted input into what to replace with and how to find reputable dealers in our zip code area 12020.
Currently leaning towards a new oil or pellet system. I’m thinking with a storage tank the system won’t need to be as large as our current system.
Anyone using Evoworld, Froling P4, Effecta Komplete III, EcoBoiler, or WoodMaster on this site?

I am running a tarm excel 2000 with a 660 gal STSS tank purchased 10 years ago which also provides DHW. I have not burned any oil in ten years and burn 8 cord a year just south of Albany heating 2200 sq ft.. Replaced the ceramics two years ago and the Tarm has run like a top for all that time. I am considering installing a pellet boiler as I have paid for wood the last 2 years and the cost of pellets is similar to wood. Used to cut and split but the body doesn't agree with that any more. I am going to sell my system at the end of this heating season. Good luck with your search. Tarms are great and I would go with a Froling personally,if they weren't twice the average cost of other systems. Waiting to see how the Evoworld reviews go. Very interesting unit. Saw an evoworld running at the Troy plant and was very impressed.

 

[uncndl1]

I am running a tarm excel 2000 with a 660 gal STSS tank purchased 10 years ago which also provides DHW. I have not burned any oil in ten years and burn 8 cord a year just south of Albany heating 2200 sq ft.. Replaced the ceramics two years ago and the Tarm has run like a top for all that time. I am considering installing a pellet boiler as I have paid for wood the last 2 years and the cost of pellets is similar to wood. Used to cut and split but the body doesn't agree with that any more. I am going to sell my system at the end of this heating season. Good luck with your search. Tarms are great and I would go with a Froling personally,if they weren't twice the average cost of other systems. Waiting to see how the Evoworld reviews go. Very interesting unit. Saw an evoworld running at the Troy plant and was very impressed.

Lot's of choices. I ordered two books on hydronics to read over the holidays.
Then will tackle additions and suggestions where appropriate.
Appreciate all the information above.
Thanks.

Sent from my SM-G920V using Tapatalk

 

[uncndl1]

Lot's of choices. I ordered two books on hydronics to read over the holidays.
Then will tackle additions and suggestions where appropriate.
Appreciate all the information above.
Thanks.

Sent from my SM-G920V using Tapatalk

Some ideas from above:
-Energy audit
-Outdoor reset controller adjusts boiler temperature based in outdoor temperature.
-New burner retention head
-Backflow preventer
-Low water cutoff switch wired in Series before triple acquast I.e. B+G RB122E
Or McDonnell & Miller Bulldog low water cutoff
-Boiler bypass valve
-New triple acquast i.e. Honeywell L8124L1011
And Honeywell L6006A
-Boiler Bypass loop
-Insulated horizontal storage tank after low water cutoff and backflow preventer.


Sent from my SM-G920V using Tapatalk

 

[peakbagger]

The guru for heating design, John Siegenthaler has several courses on line on biomass heating. Some cost money others are free

https://www.heatspring.com/app/courses/?query=biomass

 

[leon]

Good Morning,

You do not need the outdoor reset as it is needed for a digital triple aquastat control so you can cross that off your list as its a waste of money I never used or needed one in 33 years of wood burning-dont buy anything but a Honeywell L8124L1011 and the corresponding sensor well for it.

The Mcdonnell & Miller RB-122-E Low water cut off are one and the same and its a good idea to have two of them even though you have a smaller boiler with lower BTU rating.
Best installation practices for the Mcdonnell and Miller RB-122-E low water cut off are described in the installation and operators manual where both units are wired in series wherein:

The first unit is placed in the boiler steam chest and the second unit is placed in either a vertical pipe pumping away from the boiler or a second unused tapping in the boiler sump and then the BX cable is wire nutted for the powered BX(hot, neutral, ground) from the second Low Water Cut Off to one entrance knock out of the L8124L1011 to provide power to the L8124L1011 to control the boilers circulator(s), being the L6006A dump zone aquastat and circulator(if a second one is used to push overheated water to the dump zone. this is all explained very well by the literature and a well recommended licensed plumber or licensed electrician will also also help you with this with no worries.

 

[salecker]

Ditto on the outdoor reset...
Never heard of then before i built my system.
We heat through a variety of temps and have had no trouble not having one.Even at -40 for over a week our house was toasty warm without a outdoor reset.
I read about them a bit on here but never felt the need to add it after the fact,Leon has more burning time then i do and if he says not required it makes me feel good on my choice to run without one

 

[peakbagger]

Outdoor reset is for oil and Natural gas boilers, pretty much standard on new installs, I agree it wouldn't make a lot of sense for wood.

 

[JohnDolz]

Outdoor reset is for oil and Natural gas boilers, pretty much standard on new installs, I agree it wouldn't make a lot of sense for wood.

In the wood world many in Europe (and some in the US) use Outdoor Reset tied to storage to run lower flow temps.

 

[peakbagger]

In the wood world many in Europe (and some in the US) use Outdoor Reset tied to storage to run lower flow temps.

I agree, if it was a system with storage then outdoor reset could improve system efficiency, since the OP doesn't have storage I dont see much use for outdoor reset.

 

[TCaldwell]

I will substantiate john’s remarks on outdoor reset, I don’t think the emitters care from what source they are supplied from. As a matter of fact pulling outdoor reset from storage not only creates a more even heat flow but increases flexibility with firing times. Firing storage at night during the largest heat load covers the required supply temps ,as outdoor temps rise during the day the design temp goes down and most likely the lower storage temp will cover it. I agree that outdoor reset with a cold start oil boiler will have wide water temp swings due to a differential time so as not to short cycle, reducing the effectiveness of outdoor reset, but for wood storage it’s great.

 

[TCaldwell]

Peakbagger, we were both typing at the same time, you just finished sooner!

 

[uncndl1]

Sure do appreciate all the comments above. It will probably all make better sense once the books arrive and I read them.
From the owner's manual (and I'll have to look at the previous owner's install), there is a:
1. Hot water overheat control, Honeywell #4008-B-1013
2. Master hot water control, Honeywell #L8124C-1003 (high set 200, low set 180, differential 20)
3. Tridicator #PTA-1088
4. They recommend a tempering valve, Watts #70A which I do not think the previous installed (it's missing)
5. There is a tankless coil around the boiler that is currently turned off. I believe they used this in the winter for hot water but then turned it off during the summer and used electric (possibly to not burn wood or oil in the summer for hot water). A plumber turned that tankless system off and said it needed a tempering valve to avoid scalding and was dangerous without.
6. The original house has cast iron radiators in dining room and 3 upstairs bedrooms. Zone 1
7. New addition has the second zone with baseboards for master bedroom and family room. Zone 2

So from my reading above, it looks like I won't need a outdoor resent controller unless I buy a new oil burner with digital aquastat controller.
Low water cutoff switch's recommended (fairly certain that is currently not installed).
Link to the low water cutoff referenced: https://www.torrco.com/ASSETS/DOCUMENTS/CMS/EN/41150_PROD_FILE.pdf
Energy audit (this will be scheduled once home from a 3 week work assignment.
Take care.

 

[salecker]

I will substantiate john’s remarks on outdoor reset, I don’t think the emitters care from what source they are supplied from. As a matter of fact pulling outdoor reset from storage not only creates a more even heat flow but increases flexibility with firing times. Firing storage at night during the largest heat load covers the required supply temps ,as outdoor temps rise during the day the design temp goes down and most likely the lower storage temp will cover it. I agree that outdoor reset with a cold start oil boiler will have wide water temp swings due to a differential time so as not to short cycle, reducing the effectiveness of outdoor reset, but for wood storage it’s great.

Just curious...
On my system 1000 gals storage and all cast iron rads in my house except for a unit heater in my basement.Pumps run 24/7 on my system and have trv's to regulate the rads.On an average winter day of -20C i will start a fire at 5PM and shut off the boiler around 11PM,repet the next day and so on and so on.
Could you explain how an outdoor reset would help make my system more efficient or create an more even heat flow?
My rads work with 185F water and keep working down to 110F before my oil boiler kicks in.Room temps never vary if it is 0C or -40C
Thanks for the info
Thomas

 

[maple1]

Just curious...
On my system 1000 gals storage and all cast iron rads in my house except for a unit heater in my basement.Pumps run 24/7 on my system and have trv's to regulate the rads.On an average winter day of -20C i will start a fire at 5PM and shut off the boiler around 11PM,repet the next day and so on and so on.
Could you explain how an outdoor reset would help make my system more efficient or create an more even heat flow?
My rads work with 185F water and keep working down to 110F before my oil boiler kicks in.Room temps never vary if it is 0C or -40C
Thanks for the info
Thomas

Can of worms ahead - lol. I have been in that discussion before I think.

 

[peakbagger]

Take this course and then ask the question again https://www.heatspring.com/courses/mastering-hydronic-system-design/

The problem is few of us have the luxury of doing clean sheet design. I worked with I had and how much I cared to spend and went from there long before I took the course to add in my wood boiler and then my storage several years later. It was a good course but realistically the cost to design and install an ideal system far exceeds what a typical homeowner would most likely be willing to spend. I expect there is little choice between a hot tub or granite countertops instead of a slightly more efficient heating system to most homeowners. That said I have seen the reduced oil usage of adding outdoor reset on a couple of fairly basic oil systems. I have one but I dont use it as it doesn't integrate well with my current relay based control system that is piggybacked on top of my oil boiler controls. A PLC would be nice but a PITA to reprogram in few years when Windows jumps a version and the PLC program is not upgraded (been there done that at work and dont want to do it again)

I believe it boils down to running the lowest supply temperature to the emitters possible to maintain the required temperature in the house. This cuts down on losses in the piping. Installing TRVs in each room does give very fine control albeit with a higher than needed supply temp to cover the coldest room but even those systems usually use a outdoor reset on the main loop. John's approaches vary but in the case of two heating sources, what he usually ends up is circulating water through the supply loops and then reheating the return via hydraulic separators to the minimum supply temp that will maintain the building using the outdoor reset. In this case the storage acts as the primary heat source with the oil boiler isolated via a hydraulic separator until the storage drops below setpoint. At that time the storage is also isolated via a separator when the boiler is running. If I wanted to integrate a mini split (which is limited on temp output) I would get one of American Solar technics water to water units and tie that into the loop. The setup also will need two heat exchangers on the storage tank or some creative valving to use the same coil for both charging and discharging.

My system definitely has some rough edges, it went in before I took the course and its definitely not ideal but to do it over is a pretty major project and based on effectively free heat from my mini split (due to net metered solar), 3.5 cords a year from maximum wood usage from a free supply, and just about zero oil use, its hard to justify a controls and piping upgrade. My Burnham wood boiler was used and abused when I got it and someday it will finally wear out, when I do I will have to do some upgrades to the piping to fit a new Froling (or equivalent) and may take advantage of that to make improvements to the controls and piping. Long before that I would swap out my slant fin for low temp emitters and get a big effective boost on my storage capacity to extend times between firings.

Of course when I got to sell the place I expect I would need to rip most of it out to appeal to a typical home buyer. With my current setup, I break a few unions and possibly a few sweat fittings and I have regular run of the mill oil system once I move the storage tank and wood boiler out.