Still have ghost flows after installing pumps with IFCs any thoughts

[mpilihp]

Hi again, I installed Taco 007 pumps with built in IFCs in my two heat zones to stop the ghost flows through the heat zones when my wood boiler pump is running. (NOTE the wood boiler is in series with the oil boiler so the wood boiler pump is running to heat the oil boiler)

With the IFC pumps the ghost flows have certainly slowed down but it does still happen. Should it or is something else wrong? The wood boiler pump is a Taco 007.

Thanks

~ Phil

 

[Nofossil]

Hi again, I installed Taco 007 pumps with built in IFCs in my two heat zones to stop the ghost flows through the heat zones when my wood boiler pump is running. (NOTE the wood boiler is in series with the oil boiler so the wood boiler pump is running to heat the oil boiler)

With the IFC pumps the ghost flows have certainly slowed down but it does still happen. Should it or is something else wrong? The wood boiler pump is a Taco 007.

Thanks

~ Phil

Do you have a schematic? Is there a flow loop for the wood boiler when the zones aren't calling for heat?

 

[paul2e]

Does your "in series" piping push hot water into the return of other previous zones?

 

[mpilihp]

Hi Guys yes here is the diagram

http://i103.photobucket.com/albums/m132/mjenphil/WoodBoiler/Woodboilerdesign.jpg

THe heat zones have one way flow checks so water can only go in the correct way.

When the heat zones are not calling for heat the wood boiler pump circulates water through the oil boiler in the opposite direction it would normally flow when a heat zone would call for heat from the oil boiler.

~ Phil

 

[TCaldwell]

Phil, i had the same problem with the counter flow approach,i repiped to a injection system it was cured, basically at the return on the bottom of the oil boiler stack 2 closely spaced ts , the bottom t pipe in your wood supply, the one above it becomes your wood return, place the wood circ on the return to the wood boiler. Above the wood return t , pipe in your zone returns. the oil boiler supply pipes directally to your zones. the wood flow circulates outside of the oil boiler when no zones are calling, when a zone calls, the return water flows into the top closely spaced t, becoming your return water back to the wood boiler, that water proportionally displaces the same ammt of supply water from entering the bottom or wood supply t , that displaced supply water then enters the bottom ofthe oil boiler, leaving the top of the boiler to the supply rack. your oil aquastat needs to be at the lowest temp settings, as your oilboiler basically is on cold start mode while you are running the wood boiler. you can also pipe a small bypass with ball valve between top of oil boiler before supply t's to the top of the oil boiler return, thus the wood loop circ will keep the oil boiler warm enough in the shoulder seasons not to fire to make temp. the wood loop circ needs to be larger than your zone circs, my zones are all taco sevens and my wood loop is a taco 9.

 

[mpilihp]

Hi TCaldwell thanks for replying, im having a hard time understanding what your trying to explain to me. Sounds like what you are suggesting is changing the piping so that when the wood boiler circulator is running it does not go in and keep the oil boiler hot. Is that correct? My goal is to keep the oil boiler from running, our DHW is in the oil boiler so my intent is to have the wood boiler run and keep the water in the oil boiler hot without the oil burner from coming on.

Once it gets really cold out the ghost flow wont be an issue this year, next year I intend to change things around and install zone valves on my heat load zones. That way no ghost flows can happen.

~ Phil

 

[slowzuki]

I didn't spend a lot of time looking over the diagram but it appears your heat zones are in parallel with your oil boiler. When the pump runs, the pressure drop in the oil boiler and plumbing create a pressure differential in your zones in the same direction as the flow checks open direction.

 

[mpilihp]

Well my understanding is that is how it should be plumbed. Looking at the diagram for the "Simplest Pressurized Storage Solution" it shows the loads in parallel to both heat sources. That is with storage which I do not have yet, I am planning on adding storage next summer. Once I have storage the un needed heat will go to the storage and not the oil boiler so I dont think then it will be an issue.

~ Phil

 

[Willman]

I have seen debris get stuck in check causing it to remain slightly open. Teflon tape, pipe dope, rust flakes,thread debris. Pull the circ and clean the check then inspect for full closure.
Will

 

[TCaldwell]

have you tried throtteling down the wood boiler circ with a ball valve to reduce flow?

 

[mtfallsmikey]

How 'bout putting the circs on the supply side? Should eliminate the ghost flow. That's what you do with primary-secondary piping.

 

[slowzuki]

Ok I've looked it over a bit and you aren't getting ghost flows, you are pumping your zones with your wood boiler circ whenever it is on. They are in parallel with the boiler. Are you trying to achieve a primary / secondary loop with both boilers on the primary loop?

I don't want to comment to much but if you want the zones to be unaffected by flow in the primary loop, they need to connect to the loop very close to each other. I'll have to read up on the sticky thread to see whats in there now.

 

[mpilihp]

Thanks for the replys, I plumbed it by the simple pressurized diagram and from that it appeared the are in parallel to the wood and oil boilers. I understand what your saying and see because they are all in parallel flow will go through the oil boiler and the zones. Re-piping isnt an easy option so Im thinking I will put in zone valves on the loops instead and put a pump on the loop of the oil boiler. Do it exactly like the simple pressurized setup drawing shows.

Phil

 

[Nofossil]

The 'Simplest Pressurized Storage' approach uses zone valves for each zone rather than circulators. I saw an excellent installation today that did the same thing with circulators. If I can get permission, I'll sketch that up soon and post it as well, with credit to the folks who designed it.

 

[mpilihp]

Hi Nofossil thanks it would be interesting to see how they did it but im thinking they did it as slowzuki is saying with the supply and return of a zone placed on the supply side of both the wood boiler and oil boiler, then there would also need to be a circ on the oil boiler too so that when it was running it would supply hot water to the supply side of the zone. Ive seen it done and didnt think I needed to do it as I was following the design you layed out. Switching to zone valves I think is the simplest way to solve this problem. I can use the pumps im sure for other projects.

THanks Phil

 

[Nofossil]

Yeah, there are two religions when it comes to hydronic plumbing.

The primary / secondary (closely spaced tees, circulator per zone) is a more sophisticated approach that offers better control of flow through both loads and heat sources. Definitely a better choice for complex systems with very high or widely varying flow rates.

The supply / return manifold approach is simpler and uses less power, and is certainly satisfactory for most residential applications.

To make matters more complicated, some supply / return systems are implemented with a circulator for each zone rather than a zone valve.

Primary / secondary is described very well in its sticky. My intent is to add some descriptive text and a diagram for folks with a circulator based supply / return system who want to add storage. The 'simplest pressurized storage' sticky does not address this very effectively.

 

[mpilihp]

I could re-plumb to have the zone supply and return closely spaced on the supply leg (hot water source) but the controls would be a struggle and would need to add a pump to run when the oil boiler is running and it would need to be disabled when wood boiler is running. Can obviously be done but winter is here and im a slow planner.

I think the way I want to go is with zone valves and doing that for this winter I can easily add a zone valve to each zone leg and keep the zone circ, then place a relay to be activated by the thermostate and have that relay activate both the zone valve and circ. Simple and quick solution for this winter.

What do you think?

~ Phil

 

[Nofossil]

I could re-plumb to have the zone supply and return closely spaced on the supply leg (hot water source) but the controls would be a struggle and would need to add a pump to run when the oil boiler is running and it would need to be disabled when wood boiler is running. Can obviously be done but winter is here and im a slow planner.

I think the way I want to go is with zone valves and doing that for this winter I can easily add a zone valve to each zone leg and keep the zone circ, then place a relay to be activated by the thermostate and have that relay activate both the zone valve and circ. Simple and quick solution for this winter.

What do you think?

That would certainly work - a 'belt and suspenders' approach. You could remove the zone circs at a later date, though one would have to become the oil boiler circ and one could become your storage or combined load circ.


~ Phil

 

[mpilihp]

THats what im thinking, the circs would be reused at least. I also have a house I rent thnat is all one zone and with the coil of PEX im going to buy to plumb in my indirect water heater I can use to put in a second zone, one for living space one for bedrooms.

Im trying to figure out the relays Ill need to activate the zone circ and the zone valve at the same time. Seams pretty simple.

THanks for your in put.

Phil

 

[mtfallsmikey]

I did my initial firing of the wood boiler last weekend, and had ghost flows on both zones (piped P/S). I'm looking at some other install problems for the dealer I bought mine from as well...Mine is an OWB/open system though, and only loads are 2 hydrocoils. My secondary circ's are 007's too. I posted on this on heatinghelp.com, only had 1 response, which was the possibility of the primary circ's being too big. Not sure if I want to go the zone valve route, or just use a flow control valve.