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HR92 on return

Posted: Thu Jan 17, 2019 10:08 pm
by kenm
Hi,

A new radiator was installed with the TRV on the return pipe and not on the flow.
Does it matter if the HR92 is placed on the return and not the flow? Will this impact the performance of the radiator/system, or cause any other issues?

Thanks,
KEn

Re: HR92 on return

Posted: Sat Jan 19, 2019 6:27 pm
by Paul
Providing the valve body can be used in either direction (Which most can these days) then the HR92 will work perfectly, I have a few on the return flow, at the end of the day the HR92 is responding to the room temperature and just closes any valve it is attached to.

Paul

Re: HR92 on return

Posted: Mon Jan 21, 2019 8:48 am
by Richard
kenm wrote:Hi,

A new radiator was installed with the TRV on the return pipe and not on the flow.
Does it matter if the HR92 is placed on the return and not the flow? Will this impact the performance of the radiator/system, or cause any other issues?

Thanks,
KEn
All depends on the Delta P of the heating system... If you have high pump pressure from a fixed speed pump and all the HR92's are closed without a suitable automatic bypass valve, then that last valve fitted on the return with its valve seat in the same direction of flow could cause 'water hammer' where the valve seat bounces on the valve body. Not so common these days with boilers and systems with modulating pumps, but in the early days of fitting evohome this was a common problem.