Re-Gased boiler twice in six months

ThisIsWeird

Daisy_84 said:

ThisIsWeird said:

There is nothing here to necessarily suggest - other than coincidence - that the service and the subsequent pressure losses are connected in any way. They could be, of course, but we don't know.

Daisy, we need more info:

1) Make and model and type (eg 'combi') of boiler. Age?

2) What 'bar' do you pressurise your system to - 1-ish?

3) What then happens to this pressure as you fire up your boiler. Does it increase? If so, what to?

4) Does the pressure drop occur steadily over days - it's at 0.9 bar one day, 0.8 the next, etc? (Should be checked with boiler cold).

That will hopefully get us started

Why did you have it serviced? How often do you have it serviced? Why did D&G sort this - do you have a service/maintenance contract with them?

Thanks for the helpful questions. Just back to looking at this issue now. Things have been a bit insane and I’m still hoping to get to the bottom of it. 

1. It’s a Logic Combi. ESPI 35

2. I pressurised it to 1.5 on 20th January when I posted this.

3. 1.5 when fired up.

4. It’s on about .90 when cold.

I have it serviced annually. I usually use a local gas company but I stupidly decided to get a plan with D&G last year incase and part of it comes with a service. When they did the service last year they took it apart and started fixing things, even though I’d not had any issues before. It was an upsetting experience.

Thank you for the info.
We need to pad it out a bit. Do you top it up to 1.5 when cold? And then what exactly happens to the pressure when the boiler is turned on for CH and rises to its max heat - can you keep an occasional eye on it for the first half-hour from cold?
Meanwhile, can you ID the safety discharge pipe that goes outside - it'll be on the outside wall near where the boiler is located, be made of 15mm copper, and likely be pointing at the ground or bent back on itself towards the wall. See if the end is dry.

D&G have their use, and usually employ local GSs to do the work. They seem to have a policy of replacing any dodgy part that is potentially vulnerable - they want to avoid having to come out, and have seemingly worked out that the cost of replacing multiple parts in one go is cheaper than having to potentially do them one at a time! Usually that works out well for the customer.

ThisIsWeird

Daisy_84 said:

Veteransaver said:

Repressurising it only every 2 months or so suggests you have a very small leak somewhere, or maybe you've bled a radiator at some point in between?
It might not even be a noticeable leak, if it's on a valve either side of the radiator it could evaporate away quickly. Could be a tiny leak from a thermostatic valve needle.
Worth checking the valves at each radiator and also make sure the bleed screws on the rads are tight (but don't do them too tight)

Thanks. I guess I need to figure out how to check the radiators. I’ve never bled them.

Although your pressure loss is relatively small (but still too high to be acceptable), I think you would be able to recognise signs if you come across the point of leak. You'll typically find whitish or green scale and powdery residue around any fittings that are seeping, left behind as the water evaporated.
So it's worth visually checking every rad as Vet says, the bleed screws, and the valves are each end. Tbh, if there are no 'signs', then I wouldn't be worried - your amount of loss will leave obvious signs.
If you want to know how to bleed a rad - tho' there's nothing to suggest this is required - then lots of YouTube vids :-:smile:

A Q - after repressurising to 1.5 (COLD), how many days does it take for this to fall to, say, 1 bar? And, would it keep on falling at the same rate if you didn't top it up?