new combi boiler pressure drops

Room1o1

Hi, we recently got a new boiler installed as the old one needed to go. The plumber installed a combi boiler and had to pressurise the system (it's an old gun barrel system). Since installed last October we had to top up the pressure daily as it was dropping below the operation pressure for the new boiler.
Due to locked down he only came back the other day to fix the issue. It appears to fix the issue he installed a valve that auto tops up the system but didn't tell me this. He just said he put something in the system to seal the leaks.
Now the pressure is ok but I'm worried that it's still leaking but this new valve is just hiding the leaks from me as it tops up it's self automatically. The system is now connected directly to the mains supply and we had been spend about 1 minute filling it each day before he fixed it. This all sounds not rightto me. Can anyone advise if this is all ok?
Should an old gun barrel system be pressurised, connect directly to mains supply and auto tops up if pressure drops?

K.Flyer

You are right to be concerned.
If you have needed to top up the pressure on the heating system on an almost daily basis you do have a very serious leak, and to be honest, one that's not going to get plugged easily with any leak sealer.
Fitting an auto filling is Not resolving the issue, you really need to find the leak. The constant filling of a heating system with fresh water is going to cause you much bigger problems in the long run, particularly with the boiler.
It's not the boiler installers fault that the rest of the system is leaking like a sieve. But do your best to get it sorted. Might be worth considering re-plumbing the system, at least the downstairs section.

Room1o1

Thanks K.Flyer, the system is quite old so probably does need to be replaced unfortunately. I'll ask the plumber about costs when he is here next.
My other concern is that the heating system is connected directly to the mains now and not isolated from it. I read somewhere here before that this is against regs as it could contaminate water supply if it flows the opsite way during a mains pressure drop

Lenar3556

Room1o1 wrote: »

Thanks K.Flyer, the system is quite old so probably does need to be replaced unfortunately. I'll ask the plumber about costs when he is here next.
My other concern is that the heating system is connected directly to the mains now and not isolated from it. I read somewhere here before that this is against regs as it could contaminate water supply if it flows the opsite way during a mains pressure drop

Have you a cold water storage tank of any description now?

On the central heating leak, caution should be excised when converting an older open vented system to sealed. An installation which performed fine at 0.5bar or so may not be quite so fine when subjected to 4+ times that pressure.

Room1o1

Yes we still have the cold water storage tank in the attic. It just feeds the toilets and taps now. We weren't informed on the system been pressurised until after the new boiler was fitted but the system is old and possibly wouldn't last much longer anyway but a heads up from the builders would have been nice.
Still concerned about the possible contamination of the water supply for the area due to the heating system not been isolated from the water supply. I read somewhere on boards before about this regulation but can't find it now😔

The valve fitted to keep your system topped up with water should prevent your heating water from contaminating the mains water feeding it but it good to confirm the right valve was used.