TRV's

[Bullbags]

Can someone guide me on combi, or any systems for that matter.
Do you need to have one rad (usually the bathroom) in the system without a TRV on it in case other rads are turned off and the boiler fires up?
I have read that this seems to be the case. What has confused me is that I have a combi system and all my rads (9 of them) have TRV's on them, including the one in the bathroom.
Is there any set practice, guidance?
Thanks
confused.com!!

 

[nickso]

might have an internal bypass or an external one you dont know about.

 

[D_Hailsham]

What is required is a way of ensuring that the boiler does not fire up when it is not required; i.e. when the house is up to temperature. This is normally done by a Room Thermostat which is wired to form an Interlock. You should not have a TRV in the same room as a Room Thermostat - usually the hall or living room.

There is no reason why you should not have a TRV in the bathroom

There are a few boilers which will turn themselves off when all the TRVs are closed; so what make/model is your boiler?

 

[Bullbags]

The boiler I have is a Ravenheat RSF 100ET fitted approx 6 years ago. I have done work on the system and I'm fairly sure there is no external bypass on it. I don't have a room thermostats on the wall either.