Radiant Heating uneven

[ArghArgh]

House re-built from ground up 3 years ago. Bought it 3 months ago, radiant heat under polish concrete floors.

Strange issue is the master bedroom has no heat and the kitchen very little. I had a plumber out who found one of the Taco circulation pumps had blown...replaced it, he bled the lines, opened the values a bit...we saw all pipes out of the manifolds as hot so at least from there all PEX is getting heat.

I bought a iphone thermal imager, much to my surprise the master bedroom I can barely even see any warmth almost like there is no piping in there. Kitchen a bit better but seems under-flowed.

Trying to find a radiant heat expert, but while I wait, does that make sense at all, I can see all the other rooms piping getting heat, but can a run actually not get heat? Unfortunately nothing is marked either, but I also didn't spot any leaks given my limited knowledge.

Thanks.

[Ed Pawlowski]

Since it was only 3 years ago you may be able to find the original installer and find the design. It is possible they have less tubing to supply the rooms for some reason.

Could also be some flow problem but not seeing the setup none of us can tell from here. I don't know how familiar your plumber is with radiant setups.

[Dean Hoffman]

Would a good old fashioned air lock be a possibility?

[micky]

Shouldn't the homeowner have gotten a copy of the design in the first place? I'll admit I didn't get a copy of the blueprints, but my house was one of 100**, while his house sounds like it was built individually. Can't he get a copy now? I found out the architect and called him and he volunteered to send me a copy of the blueprints for free.

It turned out they didn't have the details about phone wiring that I imagined. I studied them but don't know of anything specific I used the knowledge for.

[Clare Snyder]

Maybee you should have German concrete instead of the Polish stuff? Just kidding - possibly a line has some crap in it plugging it - or someone pinched it when pouring the concrete??? I'd recommend disconnecting st the manifold and doing some sort of flow test and perhaps a pressure purge/flush

[trader_4]

I would rig up something to measure the flow rate in each line. Buy a cheap flow meter. That's the first step I see. Could be a kinked line from a bad installation?

[trader_4]

Also, how warm are the various return lines? Difference between working ones and not working? If working are warm and not working is stone cold, that would be an indication.

[Ed Pawlowski]

Never got prints for my houses. I don't think that is common.

[Ed Pawlowski]

One thing not addressed, what is the temperature in the rooms? Is it adequate? Is it too cold? It may have been intentionally designed to have less coverage.

[trader_4]

Me either. I do have a set though, I found a copy on top of some shelves that the previous owner left in the basement. I doubt that the plans would show that level of detail anyway.

[trader_4]

How about thermostats? Is there just one? Or is it zoned with multiple thermostats?

[ArghArgh]

Thanks for all the ideas and help. I don't have plans and no way to get them. Bedroom literally gets no heat, so I don't think that is by design. Single thermostat (single floor house with open floor plan).

Thinking this must be air lock, poor (or blocked) flow at the valve. Since the loops aren't marked (grrr...) two returns seem way colder than the others so that seems to be a clue.

Hard part is finding someone around here that knows radiant heat, last plumber even though he tried purging the loops said it was a "mystery". Worried the next guy that comes in will be just as unhelpful.

[Dean Hoffman]

Has anyone mentioned youtube yet? It might be worth your time.

[Anonymous]

Does each run have its own valve ? If so, you might be able to identify which 2 are the bedroom and kitchen runs by process of elimination.

Turn off one valve at a time and see if one other room goes cold. Do this for each run, and it should narrow down which 2 are the bedroom and kitchen.

Good Luck......

[Ed Pawlowski]

How comfortable is the house? That is the main thing. In my last two houses I had no heat in the kitchen but between the refrigerator and cooking, it was always comfortable or even a bit warm with the oven going. I also like the bedroom cooler, but cooler is not cold.

Certainly would be nice to have things marked. You may have already looked, but check for some sort of throttling valves to see if they are used to balance the system. They could be on the return also.

[ArghArgh]

Thanks Ed. Problem gets worse, I neglected to note the first plumber replaced one of the (three) Taco circulation pumps a week ago. it had burned out. Then 2 days ago the a grinding noise came from another one that was connected to the water tank that wouldn't stop. I went ahead on my own and replaced it with a Taco high efficiency one with an LED, working perfectly all yesterday, now the thing is throwing two flashing white LED codes which means air in the flow. It does that to protect itself. Called a guy I hope is better than the last that seems to know radiant heating better. Will be here next Wednesday, I hope he can fix it.

[Tekkie©]

On Tue, 17 Nov 2020 09:55:27 -0800 (PST), ArghArgh posted for all of us to digest...

does that to protect itself. Called a guy I hope is better than the last that seems to know radiant heating better. Will be here next Wednesday, I hope he can fix it.

Do the circulators have back-flow preventors? The loops could be fighting each other. Hope this new guy comes through for you.

[ArghArgh]

Yes they all have integrated flow control values.

[trader_4]

DIY. Buy a flowmeter and put it in the suspect lines. Or just disconnect a return from the suspect line and see if it flows. I don't see how it can be an airlock either. That can happen in a pump, if it's pushing against air. But if the lines have water in them going to all the other areas, then water would just push air out, seems to me.

[ArghArgh]

Trying to figure out how I'd bled the air from this pump. This is at this point the larger problem, this is separate from the radiant loop issue.

Maybe that image will help.