Check that the boiler instructions say its ok to do this.
sometimes we have to run a loop of pipe to dissipate the heat from the boiler if there becomes a time when all rooms/rad stats are up to temp,usually about 2 meters in length.
Does the bathroom rad have a thermostat ?? We normally use the bathroom rad as a bypass rad because its useful heat and also because if your having a shower and it gets hot it switches the rad off and you have a cold towel:(.

Some boilers say they dont require a bypass rad or loop of pipe because the boiler has its own bypass built into it( some Combis ).

Hope that helps;)

Also,if no bypass is in place,there may be a time if all rads are upto temp(unlikely),the boiler might sense this and switch off,but in combis the pump still runs on to dissipate the latent heat build up in the boiler and the pump wont be able to pump anywhere,then the overheat stat on the boiler will kick in and switch the boiler to safety mode.Then the boiler wont work until the reset button is pressed.

Duncan, Corgi installer:)

[Edited by scooby nutter - 9/7/2002 7:16:10 PM]

Consider the following:

1) Our current house has a bog-standard central heating system. There are thermostatic radiator valves on all the rads, except the one in the living room. The living room has a room stat, which shuts down the boiler when the desired temperature is achieved. The thermostatic rad valves just allow the rads to be bypassed when they get to their desired temperature. Clearly this is only ideal if the living room is the coldest in the house, as when the room thermostat gets to its required temperature it shuts down the boiler and hence all of the rads.

2) We looked at a house yesterday with a similar config. It had thermostatic rad valves on all the rads, but no room thermostats. Clearly this is better from a maintining the temperature point of view, but I thought it wasn't allowed. Once all the rads reach the required temperature, they will all be bypassed and the boiler will be pumping water around the tubes but not through any of the rads.

The question is whether (2) is bad from a boiler/heating system longevity point of view, or just from a cost point of view. I guess that once all the rads are bypassed the water in the pipes will heat up pretty quickly and the boiler will shut down via its own thermostat?

I used to rent a flat with a similar system, the combi boiler shut down when the return temp from the rads got too high.

Never had any problems with it in 2 1/2 years, don't know if it pass current regs etc.

Muf

It's not a Combi.

I guess I'll have to go and have another look. I assume this isn't the sort of thing that would be picked up by a surveyor?

Thanks for the help.