trv's

[buster12]

hi all just ned a little advice about fitting trv's as i am replacing 7 rads in the house as they are all old, what i need to know is which way do the trvs go as im not sure about which side is flow or return all my pipes are buried in concrete floors..?? can you fit 2 way trv's to any side..??[/i]

 

[meldrew's_mate]

There are TRVs which claim to be 2 way, but I've always found they are quieter on the flow end*. To find the flow end turn off the rad and wait for it to go cool with the heating still on. Then turn it on and the flow is the pipe which heats up first.

* The exception is the Danfoss revolver, which has a cunning design so you can confidently put it on either end with success.

 

[Paul Barker]

If you aren't able to run the system to verify this until you've finished the job...

If the trv is standing vertically it should go on the flow pipe. Once you get the system on if you find that the flkow pipe is at the other end of any of the rads change the trv round so it is lying on it's side then the water flows in the correct direction through it.

Personally I don 't find modern ones hammer even if they are wrong way round. The old ones didn't half complain, bang bang clonk judder judder bang bang clonk.

 

[buster12]

cheers guys is there any way by looking at the valves that are on it which way is the flow and return and also would it be wrong to fit trv's to every rad without some sort of relief loop or what ever its called..???

 

[buster12]

the word i was looking for is a bypass valve oh and if i do have to fit one where does it go..??

 

[meldrew's_mate]

Bypass valve, usually 22mm, is fitted immediately after the pump, its output goes back to the boiler via the return pipework. The flow is the bit you can blow down with it set at about 1m (0.1bar). So it 'tees' into the pump output, and the output from it 'tees' back into the boiler return.