Do all (especially system) boilers have bypass built in.

[Albumen]

About to fit a new hall radiator.

Bit tight for space.

On another thread, somebody said that my boiler, Vaillant Ecotec plus has a built in bypass. So I can put TRVs on every rad if I want.

I'm in two minds about this rad. Having a TRV on it would be good, but two lock shields actually saves about 20mm, which will help, where it's going.

If, in the future, I was to change my boiler, can I rely upon them all having a bypass internally?

Especially a system boiler, as if I ever do change it would probably be to a system boiler, to take advantage of solar heating, immersion as backup hot water supply, and get away from the bloody diverter valve, which seems to have a life expectancy of about 45 minutes.

Thanks.

 

[gigz]

Most have, but over a certain size some recommend to add another automatic bypass (easily done). Where's your roomstat ?

 

[Albumen]

On the floor at the moment! But it was in the hall. Could be anywhere really. We've got hall, kitchen, side hall/utility, stairs and landing which are all doorless, and staying like that.

I did a heat requirement calc using one of them there internet thingies. Had to pretend they were all separate rooms then add them together. Bit rough, but gave me an idea. Came out at 8000 BTU.

There's a rad in the utility, which I think is 3000 BTU. I'm trying to get the biggest output rad I can, in the smallest space, which is where SWMBO wants it. I think it gets me up to 6000BTU total.

Anyway, I suppose the roomstat could go anywhere in those rooms that this rad is supposed to be heating. It's a wireless stat.

 

[TCCHeating]

As gigz has said, most system boilers do have an internal bypass built in but some are not adequate. Your vaillant will have a 15mm adjustable bypass built in so you will probably be ok, however if you were to install a worcester system boiler fo example, they only have a puny 10mm bypass built in which is about as useful as a chocolate tea pot

It just depends on what the manufacturers say as to weather an extra automatic bypass is needed. As a rule, i never trust the built in bypasses and install an extra auto bypass wherever possible.