Determining the flow of water in a central heating system

HighamKneeDee

Hi, I need to determine the flow of water in a central heating system starting from the boiler. Long story short, we are buying an extended dormer bungalow and the one negative on the energy efficiency report is the lack of TRVs. I have mentioned this to the vendor, he is a builder and he has quoted me £500 to just install 13 valves, I don't want him to do them. I acknowledge he has to empty the system then refill after fitting. A local plumber I have spoken to wants £700 but wants to provide the TRVs. I do not see myself as a novice and will look to do these myself. But, whilst I can determine the flow from the boiler how do I tell, in a house with a concrete floor, odd configuration and boxed in pipes, which way the hot water flows into the radiators? Is there a way? I think it'll be straightforward determining this for the radiators at the start of the circuit but certainly not for all. Many thanks

buglawton

I recently had Honeywell TRVs fitted and plumber said the could be fitted at either end of rad, they're reversible so direction of flow shouldn't matter.
http://www.diynot.com/diy/threads/trv-reversible-flow.89262/
Each valve was about £20 so half your cost is parts.

HighamKneeDee

thank you buglawton, that is very useful, will have a read of that now.

Jonesya

Same with Danfoss RAS-C2, there's a plastic collar you rotate to set the flow direction so doesn't matter if you fit the wrong way around.

Checking flow is normally simple, with the system cold turn it on and walk around checking the radiator pipes, the one which gets hot first is the inlet carrying the flow from the boiler, the cold one is the outlet carrying the return back to the boiler.

If you've got a contact thermometer you can do the same thing on a hot system, the inlet should be 10-20 deg C warmer than the outlet.

HighamKneeDee

Thanks Jonesya , much appreciated, that makes sense.

sk240

Just switch on the system from cold, then the flow gets hot first :-)
Are you sure your not a novice...

Ruski

sk240 wrote: »

Just switch on the system from cold, then the flow gets hot first :-)
Are you sure your not a novice...

My thoughts exactly....

Anyhow, I'd still put the trv's on the flow - better workmanship.

Good luck.

HTH

Russ