YARBQ - yet another radiator balancing question

[Steve S]

Since fitting TRVs and new lockshield valves to all but one of my radiators I'm having some trouble. I balanced the radiator as per instructions found scattered around the web, and most of the time it's fine. However, I have a flowshare system with three position valve and I find that when both heating and hot water are 'on' the radiators only get lukewarm. I balanced the system with the hot water off. I currently have two hot water periods per day, therefore I guess the system has to work reasonably hard to get the hw back up to temp. Should I:

1. Leave it as it is
2. Have the hw on constant (except maybe at night)
3. Re-balance the rads with the valve in the CH+HW position
4. Something else

TIA for your accumulated wisdom...

Steve S

[Ed Sirett]

Depends on how you run the system.

Essentially the HW coil needs to be balanced against the rads. The rads don't need any more adjustment. If you are reasonable lucky there will be a gate valve in the HW coil pipework which can be used to adjust the flow through the coil so as not to kill the radiators.

If the cylinder is a fastish recovery type and you leave the water heating on most of the time you may get away with not having to make the adjustment.

[Steve S]

"Ed Sirett" wrote > Depends on how you run the system.

No gate valve, I'm afraid. I changed the HW program yesterday evening (now goes off at same time as CH i.e. 21:30) and collected some measurements:

Room temperature dropped to 17.6 last night. Heating on at 5:30 HW on at 6:30

Achieved a temp increase rate of 1.5 Celsius per hour over the first 90 minutes, with the HW turning on at 6:30 having little impact. To me this sounds like a fairly reasonable rate.

Thanks for the input, Ed. Much appreciated.

Steve S