Pressurised system help...please!

[bowfer]

No they didn't leave the foot pump, sorry if I gave that impression.
So, really, I should point out the various leaky TRVs we have as well then.
I've never bothered as I don't see them as a big issue.
They only tend to drip black gunge when the heating's been off for an extended period.

 

[jtsplumbing]

If you have black gunge leaking out of the valves your system is in a worse condition than you think, had no inhibitor in system for years.

 

[bowfer]

I don't doubt the system could do with a flush, but the money that entails is something we just don't have....

 

[SimonG]

Did they dump the system pressure to check the expansion vessel pressure? Half a cup of water can drop pressure.
Between 1.0 and 1.5 cold and about 1.5 to 2.0 when running hot, but depends on system size.
Does it ever get up to 3 when running?

 

[SimonG]

How long have you had boiler cover? How much you paid? How much you claimed?

Probably better off with a good local boiler man.

 

[bowfer]

With all the new stuff they've given me over the past few weeks, I'm probably quids in.
I've had a new pump, new controls and a new 'something' in the boiler.
I keep thinking they're chasing their tails and missing the real problem, which is a lack of pressure.
I'm correct in thinking a lack of pressure would make the boiler and pump 'run on' after the controls have gone off?
The pump is really loud when this happens, which suggests a lack of water.
Once the heating 'officially' comes back on via the controls, the pump gets progressively quieter.

 

[gmartine]

You need to get them back in, the boiler should not be firing if the controls are off that just sounds bizarre. Pump can run on when the boiler isn't firing certainly but the lack of water you describe sounds like an airlock. When the system is pressurised you should be able to bleed it out.

 

[bowfer]

I think the boiler (and pump) running on were why they fitted new controls.
They obviously blamed a control panel problem.
But I'm not convinced, I think it's all to do with lack of pressure in the system due to the fill-loop not working etc.
They're visiting tomorrow.

 

[Best]

If you have any motorised valves (zone valves that will have a square plastic or metal head) then they can fail and put power to boiler and pump.
But I would be astounded if the boiler service blokes didn’t check that.
Your TRVs leaking when heating off means they are always leaking and this will contribute to system water pressure loss

 

[heatservice]

EV air pressure can only be set once you have got rid of the system water pressure, air pressure should be around 0.9 bar, if water leaks from the schroeder valve then the EV needs replacing.