Best position for automatic bypass valve

[albapa]

Hi all,

I'd like to install an automatic bypass valve on my central heating system. It's a pressurised system using a Worcester Greenstar 27 CDI combi boiler. I have a few questions:

1) Apart from the obvious (that it should be between the feed and return pipes of the CH) are there any recommendations (i.e. minimum distance from the boiler etc.) where to position it?

2) Does anyone know the minimum flow requirement of my boiler? I managed to find the characteristics of the built in pump, but I'm still missing this information. That'd help me figure out the pressure setting of the bypass valve.

3) Any suggestions which bypass valve to use? Their prices vary wildly between £8.35 (Zilmet from JTM) and £46 (Honeywell from Screwfix)?

Thanks in advance.

 

[Riley]

I must just ask. Why didn't the installer put one on? Or are you the installer?

 

[albapa]

This is an old installation which I am upgrading. Each rad will have a remote controlled TRV with temperature sensors (so each will be able to demand heat from the boiler) but in this situation it can occur that all TRVs are closed but the boiler pump needs some overrun, hence the need for the bypass valve.

 

[Dotty]

Not being funny, and with all due respect but I should get a pro in to do this if I were you.

The reason for this is that when you refill the system you will need to vent the boiler. Which involves removing the case, which you can't do because you're not a gsr.

 

[Dotty]

I'm sure you get a control stat with them systems.

Leave a radiator, bathroom or hall, with two lockshields. Hall if you've a control stat, bathroom if not.

This'll avoid a full drain down.

 

[albapa]

Luckily, my boiler has an automatic air vent so there is absolutely no need to remove the cover.

Yes, having a rad acting as a bypass is an option. But I know it is also possible to install a system like I described so in any case, I think my questions are still valid and I'd be grateful if someone could give any advice.

 

[Dotty]

Oh right. You're one of them.

"I haven't gotten the answer I wanted so I'll keep asking the question."

Re-evaluate your expectations.

Thread closed