New wood boiler operating issues

[zero2491]

I recently bought a house with an outdoor NCB-175 wood boiler with a propane tank back up. The outdoor wood boiler is tied into my propane water heater and propane indoor furnace, with heat exchangers, and i have radiant heating.

Last winter (my first winter at the house) i fueled the wood boiler consistently, however i burned through a lot of propane. Approximately 4 -5 tanks (330 gal tank for 280 filled lbs).

My first question is burning 8-10 cords of wood, along with that many tanks of propane right? I don't have any leaks in the lines, as this summer I only used, maybe half my propane tank.

I am not 100% sure still how to run it correctly, and the last owner did not give me alot of instructions, and of course nature's comfort is no longer around.

Note: we kept our house between 70-74. So, my second question is, am i supposed to set my indoor thermostat (only tied to indoor furnace) to desired temp or is there something i am missing.

 

[hobbyheater]

Square ft of the house , year of construction , type of underground lines ,how are the lines tied to the boiler , and propane furnace or boiler?

 

[brenndatomu]

Last winter (my first winter at the house) i fueled the wood boiler consistently, however i burned through a lot of propane. Approximately 4 -5 tanks (330 gal tank for 280 filled lbs).

My first question is burning 8-10 cords of wood, along with that many tanks of propane right?

Sounds like something is real wrong...but like HH just asked above, need some data first.
You should have been able to heat an uninsulated barn with all that fuel!

 

[zero2491]

Square ft of the house , year of construction , type of underground lines ,how are the lines tied to the boiler , and propane furnace or boiler?

my house is 1400sqft, it's a 1.5 story house with finished basement. the wood boiler is tied into the detached garage as well. garage is insulated and i only set it to about 55 degrees. wood boiler is tied into garage with a water to air exchanger and a fan pushes it to the garage. Garage is about 800sqft and it has a curtain divider to cut that down in half to only heat where the cars are.

the house was built in the 70's. it stayed cool this summer with some window AC's and didn't seem to warm up fast. walls are drywall with fiberglass insulation. attic is blown in insulation.

house has 3 zones. basement, 1st and 2nd floor.

i have attached pictures of how it's tied into my water boiler and furnace.

 

[hobbyheater]

One problem I see you have very poorly insulated underground pipe !

 

[brenndatomu]

One problem I see you have very poorly insulated underground pipe !

Yup, that stuff is just one step better than no insulation....and if it is laying wet, about the same as none. That'll eat up some serious BTUs...number one rule with outdoor boilers....don't cheap out on the underground lines!!

 

[sloeffle]

+3 on the underground pipe.

Looks like a bit of a hack job to me. My guess is, the plate exchanger isn't making much hot water too. Are those galvanized fittings on the hot water heater ?

 

[zero2491]

Yeah the last owner did alot of things himself. I know when we first moved in the hot water tank was broken and only way we had hot water was from the wood boiler heating it (very hot!) until i replaced the thermo coupler in it. And i would say the plate exchanger is making at least some hot water. When the boiler was running those pex pipes you almost could not touch.

But yes i believe there is galvanized as well as PVC. if you look on top of the boiler i believe my cold water inlet is pvc which is ran right back to my pressure tank for well water.

It also appears he "daisy chained' the plate exchangers together. the hot water comes in to the hot water tank then loops into the plate exchanger for the furnace then back to wood boiler.

seems like i may be better off this year to run just propane until i get some things resolved.

i would say i fed that boiler 3 times on average a day. 1 time around 5-5:30 am, then after i get home from work around 4:30, sometimes the wife would feed it while im gone, and then right before bed. On warmer nights i could get away with first thing in morning and then at night. Our worst night was wind chill of -30 and i fed that about every 3hrs. it would not be fully empty after 3 but at least halfway if not more to the point of almost empty. enough there to throw logs in and not have to relight. I only get hardwood to feed it.

 

[hobbyheater]

The heat plate exchanger should be plumbed into the cold water line entering the the propane tank. The way its hooked up now at this time, it could be heating the lines going back to the wood boiler. There should also be a thermostatic mixing valve on the hot water line leaving the hot water tank.

 

[jblnut]

Do you have a way to measure your supply and return temps at the house and wood stove ? It'd be great to know if the heat is making it to the house with the poorly insulated underground pipe.

As far as the propane goes ...... I can dig up a picture but I put a mechanical aqua stat on the supply line that goes to the furnace that intercepts the "fire the LP" signal from the house thermostat. If the water temp drops below 120f it'll trip and allow the LP to fire. That way the same thermostat controls the fan for both wood and LP heat. Simple stuff. Keeps the LP from kicking on unless the stove gets too cold.

I put an InkBird BBQ thermometer on the supply and return lines on the back of the stove so I know how hot it is whenever I want to look. I also set it to alert me when the supply temp drops below 150 which usually means it's out of wood or something else is wrong.

 

[zero2491]

The heat plate exchanger should be plumbed into the cold water line entering the the propane tank. The way its hooked up now at this time, it could be heating the lines going back to the wood boiler. There should also be a thermostatic mixing valve on the hot water line leaving the hot water tank.

I was always curious as to how my current set up worked. I wasnt sure how it currently regulated temperature. would this thermostatic mixing valve work?

 

[zero2491]

Do you have a way to measure your supply and return temps at the house and wood stove ? It'd be great to know if the heat is making it to the house with the poorly insulated underground pipe.

As far as the propane goes ...... I can dig up a picture but I put a mechanical aqua stat on the supply line that goes to the furnace that intercepts the "fire the LP" signal from the house thermostat. If the water temp drops below 120f it'll trip and allow the LP to fire. That way the same thermostat controls the fan for both wood and LP heat. Simple stuff. Keeps the LP from kicking on unless the stove gets too cold.

I put an InkBird BBQ thermometer on the supply and return lines on the back of the stove so I know how hot it is whenever I want to look. I also set it to alert me when the supply temp drops below 150 which usually means it's out of wood or something else is wrong.

I know my outdoor wood boiler has a temperature guage on it, which i believe is set to 160. i dont have a way, yet, on the interior to measure the temperature, only if i added a drain valve to the lines.

 

[jblnut]

I know my outdoor wood boiler has a temperature guage on it, which i believe is set to 160. i dont have a way, yet, on the interior to measure the temperature, only if i added a drain valve to the lines.

If you have your boiler set to heat to 160 it's very unlikely that the return temp is above 140. When it's below 0F here I need to have it at 185F to keep the return temps above 140F when the house or shop is calling for heat. When the water is just circulating with no heat demands it loses about 4F going to the house and back and 1F going to the shop and back.

I base the temp the boiler runs at according to the return temp of the water. If it drops below 140F I raise the boiler temp or lower the heat load. I have the mixing valves in the house set as low as they go and the return temp stays above 140F until it drops to -30F with some wind. I haven't set the stove above 190F yet as that's as high as the manufacturer says it can go. I know guys that set it to 195-200 when it's cold but that seems a bit hot to me !

I put one of these thermometers on the supply and return pipes on the back of the stove. I taped the probes directly to the pipes with some foil tape and wrapped them with pipe insulation. It's really nice knowing at a glance where the temps are !!

Amazon product ASIN B07XNTJKY4

 

[maple1]

I would bet more than half your heat is going into the ground.

 

[zero2491]

I would bet more than half your heat is going into the ground.

what kind of insulated pipping should it be then?

 

[brenndatomu]

what kind of insulated pipping should it be then?

Thermopex is good...so is Insulpex by Rehau

 

[jblnut]

what kind of insulated pipping should it be then?

The kind of piping that has insulation wrapped around it is inexpensive but also not very good at actually insulating. When moisture creeps inside the pipe the insulation becomes wet and the pipes lose a lot of heat trying to warm up the underground water.

The brands listed above all have a similar outer shell but have a ridgid foam injected into them to be the insulation. It's like spray foam inside a pipe. I lose 1°F in the entire 200ish feet from the stove to the shop and back again with the fancy expensive pipe. I know you have that stuff now but if you ever even think about replacing it even for a moment spend the money and do the spendy stuff ! I figured "but once, cry once" and I definitely shed a tear when I wrote out a $5k check just for the underground piping but it translates to a lot less wood being needed each season.

I've got a neighbor that rigged up a homemade deal to inject his underground boiler pipe that is of similar construction to yours with spray foam and it worked very well for him. The long and short of it was he got a loooooong 1/4" plastic pipe shoved into the boiler pipe and injected foam into the 4" pipe that contained the wrapped PEX lines and pulled the 1/4" line out as he put the spray foam in. He says it worked very well and cut his wood use in half from one year to another with no other changes. Might be worth trying to figure it out 🤷‍♂️