Newbie Needs Assistance

[CombatVetFamilyMan]

Ok, the plumber came over today. He took apart the Grundfos pump for the 2nd floor zone that I've been having overheating problems with. He said that it looked like there was some hard water build up inside and that he cleaned it. I doubted this would solve the issue, but he's the expert, and I'm just the home owner. I asked if that if the forward and return manifolds should be connected and he advised me that they were already connected inside the LP boiler. He politely said that the whole issue could be operator error. I've been reading everything on this thread and others too, especially the posts from mikefrommaine, Clarkbug, and flyingcow, and felt pretty good w

hen I defended the "operator error" claim. The plumber provided me with the schematics he used.

 

[CombatVetFamilyMan]

Not sure if it matters, but I have three zones, and the circulator pump that is closest to the boiler is pumping water to the right, away from the boiler, into the LP boiler

 

[Clarkbug]

Ok, this definitely helps us figure out how your system works. Thanks!

The pump on the bottom of that diagram should be running whenever your wood boiler is fired up. You said its pumping into the LP boiler, that should be coming out of the top (supply) of your wood boiler. The other line that heads back to your wood boiler should go through a tempering device for temperature protection, then into the bottom (return) of your wood boiler. Your house zones then return into the supply from the wood boiler. This will keep your LP boiler warm. Not the best arrangement, as it lowers the supply temps to your house from your wood boiler, but its the exact same arrangement I have It works so far, and I cant complain, cause I havent burned a drop of oil yet this year.

Having said all that, it really doesnt say for sure why your house is overheating. My guess would be that the wood boiler pump (the one on the bottom of the diagram) is also inducing a flow through your second floor zone, even if the second floor pump isnt running. Are there any other check valves anywhere in your system?

And really, tell your guy that it cant be operator error if your house overheats. You cant screw up adjusting the thermostat.

 

[flyingcow]

FWIW- My heating system(oil ) was installed 16/17 yrs ago. Wood boiler, 4 or 5 yrs ago. My zone valves are auto mags, 16/17 yrs old. They're getting weak. When i fire up the wood boiler, the increased heat/pressure will bypass(overwhelm?) the zone valve on my first floor. Not a biggie as we need the heat anyways. But once in a while my upstairs zone will do the same. We keep the second floor at 60/62. But if this happens and heat my upstairs to 64/66-ish, than it's too hot for us to sleep. That story is probably not going to help much. Someday I will remember to by new magnets for the zone valves.

 

[mikefrommaine]

Here's what I think may be happening.

The wood boiler pump is pushing through the internal flow check whenever no zones are calling for heat and the tarm is at temp. It only takes .3 psi to open a flow check. The diagram assumes the flow checks will prevent water from the wood boiler will not go into the zones when the tstats are satisfied. But I think since the piping to and from the boiler are only 1" and the supply header is 1.25" enough pressure is applied to the flow check to open it and allow some of the flow to go through the zones.

 

[ewdudley]

Here's what I think may be happening.

The wood boiler pump is pushing through the internal flow check whenever no zones are calling for heat and the tarm is at temp. It only takes .3 psi to open a flow check. The diagram assumes the flow checks will prevent water from the boiler will not go into the zones when the tstats are satisfied. But I think since the piping to and from the boiler are only 1" and the supply header is 1.25" enough pressure is applied to the flow check to open it and allow some of the flow to go through the zones.

But the parallel path is reverse flow through the upstairs zone and pump. And upstairs zone has more thermo-siphon to work with. If check valve for upstairs zone is not there or not seating that would explain it.

As a side note, it is very disappointing that both the professionals at FWW and the plumber on site failed to appreciate that, as Clarkbug points out, the wood boiler flow through the gas boiler should be going the opposite direction.

 

[rkusek]

But the parallel path is reverse flow through the upstairs zone and pump. And upstairs zone has more thermo-siphon to work with. If check valve for upstairs zone is not there or not seating that would explain it.

As a side note, it is very disappointing that both the professionals at FWW and the plumber on site failed to appreciate that the wood boiler flow through the gas boiler should be going the opposite direction.

Doesn't it make you wonder if someone at FWW mislabled it?

 

[maple1]

I can't tell since it's off the diagram, and it's not been clarified (unless I missed it) - does the wood boiler water go out the top of it to the LP, then return back to the bottom of the wood boiler? That diagram you posted suggests it might be the opposite - which is not right.

I think what is happening is simply that when the wood boiler circ is running, it's somehow pushing flow past the zone check valve (with 'added help' from the increased convection force from it being a higher zone) - although, as ew said, that shouldn't really happen either as the zone flow should be tending reverse with no call for heat.

As Clarkbug said, you should have return temperature protection plumbed in the boiler loop in the form of a tempering device (e.g. a danfoss valve). I'd consider that even more of a possible issue than the hot upstairs - if there's no return temp protection, it could cause damage to your boiler. Is it recommended or spec'd in the Tarm manual? I know it is in mine. Although, admittedly, without storage your return temps won't be as low as they could be with storage - so it might not be as serious as it first seems.

I think my suggestion would be to maybe add a zone valve to the zone piping - unless I've missed something, and unless his cleaning of the check has fixed it, that is. My system has a zone valve for each zone & only one circ - I never could figure the benefit of going with zoning by multiple circs, especially now with pumps like the Alpha.

And trying to attribute this to operator error is just wrong and even silly - did he say exactly what about how you were operating it is in error? If he was going there, he should have also explained why.

One more thing - is your wood boiler circ a 3 speed? Is it set on low? If it is a 3 speed, and not on low, try switching it to low.

 

[CombatVetFamilyMan]

Apparently my last post didn't post half my message (def operator error). Here's the email FWW sent to the plumber along with Tarm schematic, I'll attach the the LP set up too.
Circ is set on low.
MESSAGE
Sent: Tuesday, April 24, 2012 8:42 AM
Subject: eastman way
This is the closest to what we have at [deleted my address here]. Make sure he gets the Automag zone valve from the Tarm Guys Powered closed
The mixing valve shown is just a lo-temp option , Not needed here. Above the the boiler side concept drawing. More I look at this a modine might not be a good dump choice , Fan will not work very well with no power will it. Guess fin tube is the best choice , Mabye dump into 1st.floor baseboard zone after all…
END OF MESSAGE

 

[maple1]

You mentioned in your first post the boiler dumps into the second floor zone - but that it hadn't gotten hot enough to dump yet. But the second floor is where the issue is (coincidence?), and the dump circuit is not shown on the plumbing diagram - so how does that tie in and how is it configured? May or may not be an issue - but seeing it in the Tarm diagram, and not seeing it in the plumbing diagram, and seeing it mentioned in the email 'make sure he gets the automag' kind of raises some questions.

 

[ewdudley]

You mentioned in your first post the boiler dumps into the second floor zone - but that it hadn't gotten hot enough to dump yet. But the second floor is where the issue is (coincidence?), and the dump circuit is not shown on the plumbing diagram - so how does that tie in and how is it configured? May or may not be an issue - but seeing it in the Tarm diagram, and not seeing it in the plumbing diagram, and seeing it mentioned in the email 'make sure he gets the automag' kind of raises some questions.

I think the auto mag is directly above the wood boiler. Wood boiler supply is on right side (as you face the boiler) and tees towards the back to feed system and tees towards the front to feed dump circuit.

 

[maple1]

Yes, I now see what I think is a zone valve right above the boiler - but I'm still questioning the dump circuit since it isn't shown on the plumbing diagram and the email seems to imply it's the owners responsibility and it was said (I think) that the second floor zone is the dump circuit. Which is coincidentally where the problem is. I also don't see in the pics any extra piping that would tie into the zones if it was dumping to the second floor zone.

Wild shot but is there a chance it's dumping all the time for some reason? Like a n/c valve rather than a n/o, or it's not wired right? I'm not familiar with Automags so can't recognize it as an Automag in the pic - but it does kind of look like one of my zone valve motors on top rather than a magnet (might be me or the pic though).

 

[ewdudley]

Wild shot but is there a chance it's dumping all the time for some reason? Like a n/c valve rather than a n/o, or it's not wired right?

OP reports above that dump zone aquastat was set too low and that was the cause of a prior episode of upstairs overheat. That problem is supposed to have been resolved by adjusting the dump zone aquastat, but there reportedly is still some flow through the upstairs circ. If upstairs circ is not running then the only way the wood boiler flow can go through the upstairs zone is if there is reverse flow through the upstairs circ.

 

[mikefrommaine]

. If upstairs circ is not running then the only way the wood boiler flow can go through the upstairs zone is if there is reverse flow through the upstairs circ.

I'm not understanding what you mean by this completely.

This is what I was thinking:
When no zone circs are operating and the tarm is at temp the wood boiler (bottom of pic) will be running and flow through lp boiler. So water is being pumped up and out of the lp boiler. It then goes up the right most of steel pipe (1.25?) For things to work right the flow should then go through the fist t into the (1"?) copper pipe. The internal flow checks should block any flow through the zones. But isn't it possible that enough pressure is being applied to the flow check to allow it to open?

Fwiw I used a tarm diagram (two boiler direct) before I had storage that worked great. Id have your plumber follow that diagram.

 

[mikefrommaine]

MESSAGE
Sent: Tuesday, April 24, 2012 8:42 AM
Subject: eastman way
This is the closest to what we have at [deleted my address here]. Make sure he gets the Automag zone valve from the Tarm Guys Powered closed
The mixing valve shown is just a lo-temp option , Not needed here. Above the the boiler side concept drawing. More I look at this a modine might not be a good dump choice , Fan will not work very well with no power will it. Guess fin tube is the best choice , Mabye dump into 1st.floor baseboard zone after all…
END OF MESSAGE

View attachment 88990View attachment 88991

Maybe I'm reading this wrong. But is the "professional" saying that a 3 way bypass to keep return temps up not needed? I didn't see a danfoss or termovar in the actual pics...

Who actually sold you the tarm? And have you talked to them?

 

[ewdudley]

Maybe I'm reading this wrong. But is the "professional" saying that a 3 way bypass to keep return temps up not needed? I didn't see a danfoss or termovar in the actual pics...

It would probably be better if there was a return protection mixer, but in a situation like this with no storage there's a case to be made for not bothering with one. If the wood boiler can keep up and the loads are baseboard then return temperature shouldn't be a problem. But again, it would be nicer to have return protection and not worry about it.

 

[ewdudley]

I'm not understanding what you mean by this completely.

Just look at the flow leaving the wood boiler circ. It comes to the tee where it can go into the bottom of the fossil fuel boiler or it can go backwards into the return manifold. Only the zone pumps can force flow forwards through the load circuits. The wood boiler circ can't pump forwards through the load circuits because then it would be pumping against itself where the load circuits tee back into the line that goes to the bottom of the fossil fuel boiler.

 

[mikefrommaine]

Just look at the flow leaving the wood boiler circ. It comes to the tee where it can go into the bottom of the fossil fuel boiler or it can go backwards into the return manifold. Only the zone pumps can force flow forwards through the load circuits. The wood boiler circ can't pump forwards through the load circuits because then it would be pumping against itself where the load circuits tee back into the line that goes to the bottom of the fossil fuel boiler.

Thanks, now I understand.

 

[ewdudley]

Thanks, now I understand.

Took me a while. You want to think the pumps should obey the arrows 'cause that's how they're drawn.

 

[mikefrommaine]

If only it was that easy

 

[Clarkbug]

The email that the OP posted here frightens me a little, just based on the tone and attitude in it.

OP, I would tell the installer that they need to come back and put in the return water protection for you ASAP. as EW said, you can make a case for not having it, but I would check to see if Tarm will honor their warranty if one is not installed. If not, make the installer put it in.

Also, there should be a difference between an overheat zone and a dump zone, at least in my mind. I have fin tube installed with an automag valve along the ceiling of my basement in case of power outage. But I also have an aquastat installed in the top of my boiler that will turn on one of my zones if the boiler temp gets to high. Do you have one or both of these features?

As an aside, the way your system is installed is common around here for folks that use an OWB, so a lot of heating guys just plumb that way all the time. It keeps a sidearm hot water heater usable regardless of the fuel source getting used, so they just always install them that way. I found this out after I had used a different Tarm diagram,and came home to the one that you posted above. And strangely enough my guy talked with the folks at Webb........ Hoping to get that changed out to closely spaced tees or a TwinTee this spring.

 

[Ldl0431usmc]

It doesn't look like the boiler was piped according to any diagram Tarm Biomass has produced. From what I can see in the pictures, it was piped in parallel with the existing gas boiler. Using the Tarm drawing to get the icons, draw what you have and I'll see what I can do to help you get this thing straightened out.

 

[ewdudley]

It doesn't look like the boiler was piped according to any diagram Tarm Biomass has produced. From what I can see in the pictures, it was piped in parallel with the existing gas boiler.

It's hydraulically equivalent to the Tarm 'Solo4' diagram, minus the wood boiler return mixer valve. It fact Tarm titles it "Two Boiler Parallel Design, No Thermal Storage".

It's a viable configuration as long as the system emitters work well enough despite mixing wood boiler supply with system return, as Tarm points out in the applicability note.

 

[BoilerMan]

I would check to see if Tarm will honor their warranty if one is not installed. If not, make the installer put it in.

Also, there should be a difference between an overheat zone and a dump zone, at least in my mind. I have fin tube installed with an automag valve along the ceiling of my basement in case of power outage.

I think if the one could make an upstairs loop work well for the gravity loop if the piping allows for good gravity flow. Generally though the dump is not wanted upstairs so it is in the living room etc, but the upstairs could be used for both. Pipe a NO zone valve (automag) i parrellel with the flow check to allow for gravity flow. I think Maple1 does this if I recall.

The Tarm and warranty is an excellent point! I'd check in the manual or email them and find out for sure.

TS

 

[Clarkbug]

I think if the one could make an upstairs loop work well for the gravity loop if the piping allows for good gravity flow. Generally though the dump is not wanted upstairs so it is in the living room etc, but the upstairs could be used for both. Pipe a NO zone valve (automag) i parrellel with the flow check to allow for gravity flow. I think Maple1 does this if I recall.

The Tarm and warranty is an excellent point! I'd check in the manual or email them and find out for sure.

TS

I dont disagree with you Taylor, that it could be made to work using an upstairs zone. I just didnt get that impression since the e-mail he had posted talked about switching from a Modine (Unit heater) to fin tube for a power outage dump zone. My thoughts are that something is wired up funky with the aquastat/configuration of the loops for his overheat. My post above was just to try and help get all brains here on the same page for problem solving.

Maybe the way its wired is the issue. Sounds like the second floor zone always runs when the wood boiler is activated, so maybe there is some linking between aquastats going on?