Problem with TRV Valves

tomz

I have a three story house with seven radiators and cast iron baseboard in the kitchen all on one zone. There was 2" supply and returns with 3/4" to the radiators. It sucked. After reading Dan's book Pumping away I tore out the 2" pipe and installed 3/4" pex in the basement. I installed danfoss TRV's on each radiator, installed the circulator pump on the supply side and plumbed everything else in as per the book. It works great already noticed a reduction in coal use.

 The only problem that I have is the radiator on the third floor. When the valve opens or closes it makes noise until it opens or closes all the way. These valve seem to work slow so it takes awhile. The system pressure is set at 15psi I raised and lowered it with no change. I changed the adjustment on the bypass valve in big and smell increments with no change.  One thing that I did find out is that it only does it if all the other valves are closed. If I open any other valve by turning up the operator it stop making the noise immediately.

If your only answer is going to be call a proffessional or send in pics to post on the ugly wall please don't waste my time. I talked to two plumbers before doing this and both said that you can't put the circulator on the supply side and didn't even hear of the trv's

Alan (California Radiant) Forbes

Pump

I'd say your pump is the problem.  With only one radiator calling for heat, the pump is trying to pump everything through the one radiator and you are hearing that flow through the TRV.  In order to alleviate the problem, you will need to invest and install a differential pressure bypass valve which will divert unneeded flow back to the return piping.



Caleffi makes a good one.

KAB_2

Your almost there

It will take a while, basically any free days and nights you have. Keep on adjusting all the valves until the 3rd floor stops making noise. Depending on your boiler, there'll be quite a few heating cycles per day, make only one adjustment per cycle and see how not only the third floor reacts, but the rest of the system.

Alan (California Radiant) Forbes

Bypass

I see now that you already have a bypass valve.  It could be that your pump is too large.  What is the make and model?

tomz

pump brand

Thanks for the reply. It is a taco 007 F-4. It makes sense what you are saying but when any other valve is the only one that is opening or closing it works fine

tomz

pump brand

Thanks for the reply. It is a taco 007 F-4. It makes sense what you are saying but when any other valve is the only one that is opening or closing it works fine

Robert_25

coal?

Hey Tom, what are you running for a coal boiler?  I heat my house with an EFM 520.

tomz

efm

I am running an EFM 520 also