Chattering TRV

Arthur

Well I know the Heimeier TRV's don't like the flow the wrong way as found out the hard way a couple years when I couldn't find out which was flow and which was return on a rad.

Eric Peterson_3

Chattering TRV

I installed four Honeywell TRVs in the second floor of my house 2-3 years ago. They have worked flawlessly except for one small problem. Once or twice a year I notice a slight hammering in the system, similar to a sound in the water pipes if someone were to rapidly open and close a faucet somewhere.

Anyway I have traced the problem to one of these TRVs - the condition ceases if I make a small adjustment one way or the other to the thermostat portion of the unit.

I don't think it is the thermostat as I have swapped this with one from another room and still had the problem occur.
My questions:
1) anyone else seen or heard of this?
2) could this cause some failure to the system?
3) any proposed remedy other than replacing the valve?

The valve is a Honeywell-Braukmann #V110F1018, piping is black iron pipe, pumping away, radiator in question is the closest one to the boiler in a zone with 4 TRV-controlled radiators and 4 other radiators (no TRVs).

Thanks,
Eric Peterson

Unknown

that happens when almost all of the flow is stopped

by the TRVs, and the pump is still trying to move water.

A pressure bypass regulator should be installed, or the pump should be shut off when you don't need any heat.

Noel

Bill_17

Chattering valve

Eric,
Try to verify the flow direction versus the flow directional arrow on the valve. TRVs will chatter when in the slightly open position if installed in the wrong direction. To test, turn the TRVs dial to a low setting and let the piping & radiator cool, then dial a high setting, you should be able to measure which side of the valve/radiator is getting hot first.

tim smith_2

chattering

I would bet on wrong flow direction. just found 6 out of 15 installed wrong. Tenants been >??<?><"{L"{L:. will fix next week. Not our mistake. hhaaa haaa

Eric Peterson_3

Good detective work!

When I installed the TRV I simply replaced the old valve. After running down to the basement just now to check the pipes, well the flow is indeed reversed! That is to say, this radiator was originally installed with the shutoff valve on the return side instead of the supply side. It did not make much difference with a shut-off valve but of course it does with a TRV.

I guess I got lucky with the other two older radiators where I also replaced the valve. Will have to check those too. The fourth TRV radiator I installed myself and I know that one is OK.

No pressure bypass is needed as there are also four other radiators without TRVs (i.e. always open) in this zone.

Rather than mess with the radiator fittings (this is a big heavy old radiator) I will probably just change the piping in the basement as it is easily accessible.

Thanks for your help.
--Eric

Aidan (UK)_2

TRVs

Most TRVs now sold will work with the water flowing in either direction. If you can get one of the more recent TRVs, it's likely that it will be a straight swap for the old one, with minimal disturbance to the pipes and radiators.

DWood

multi directional

Aidan (UK),
How fortunate to be on the side of the pond where hydronics rules. To the best of my knowledge, none of the TRV manufacturers that distribute in North America have decided to bring the multiflow TRV's across the pond. I suspect it is due to low flows, smaller sizes and demand, but perhaps one day we too will see those problem solvers.
DWood

Mark Eatherton1

Omnidirectional TRV's

would work great on those systems requiring a 4 way reversing valve!

ME

Aidan (UK)_2

Really?

Well, I'm gobsmacked!

Ignore the previous then, Eric.

A business opportunity for someone here, Dennis? I've just put your excellent Danfoss RAS-D TRV's in my house. I have no idea which are on the flow and which on the return. They all work fine.