Jump to content

Combi boiler / central heating problem - short cycling - faulty valve?


Conor

Recommended Posts

We've just moved in to our rental accom and the combi boiler has been dodgy since day one. Tripping out after just a couple hours of running. 

 

Last night, it failed to heat the rads at all. From what I can see, the boiler is heating the CH water as normal, but instead of circulating around the system (red arrows below), it's flowing through a bypass (yellow arrow) and causing the boiler to shut off after just a few seconds.

 

I'm guessing this valve (green) is at fault? Is there anything I can do easily (like adjust it?). Valve ranges from 0.5 to 0.1, I'm guessing it's some sort of prv? Or am I going to have to ring the land lady?,

 

Edit: from a quick search it seems to be a faulty automatic bypass valve. I tried it fully out (0.1) and fully in (0.5) and doesn't make a difference.... Oh, and it drops water now...

IMG_20200117_121925~2.jpg

IMG_20200117_122015~2.jpg

Edited by Conor
Link to comment
Share on other sites

The automatic bypass will pass water when the normal water flow route is shut.

 

IF for example all radiators have thermostatic valves, and all rooms are up to temperature, then water will not flow through the radiators and the bypass is doing it's job.

 

Go and ensure at least one radiator has it's TRV turned up to maximum and try again.

 

  • Like 1
Link to comment
Share on other sites

Just moved in? Has the heating been off for awhile? I wonder if it's full of sludge that has settled out while it was off? We had that problem in the house we rented.

 

Should be down to landlord or his agent to fix. Ours arranged an engineer to call but all he did was get the sludge stirred up so it would circulate. I suggested to the landlord he should consider getting it drained and inhibitor put in but got no reply.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...