Vaillant Thermocompact pressure since BG Annual Service

[fiveminutejob]

Have read the FAQ's, but am a bit puzzled by the pressure readings on our Vaillant ThermoCompact boiler since its annual service by BGas last week. Boiler had been working fine all year.

When I checked the pressure dial a day or so later with the CH going, the needle was pointing to around 2.5 - not the usual 1.5+ I previously used to see when I randomly checked it over the years, giving it the occasional top up via the filling loop when necessary. Now, when the CH & HW is switched off, the needle drops to zero (it normally settled no lower than about 1.0+ when cold).

The whole system is 8 years old, providing central heating and hot water. CH side is sealed (no header tank in loft). Hot water has large loft tank and cylinder in airing cupboard.

He did change a TRV while here, but since his visit the rads have been bled (no air).

- Is there anything that might explain the odd pressure readings after the service?
- Is this anything to worry about, needing BGas to be called back?
- Or will it just settle down on its own?

Any advice/comments would be welcome. Thanks

fmj

 

[petit_pablo]

Expansion vessel requires recharging. You coulddo it yourself but why bother when you pay BG to do it

 

[fiveminutejob]

Thanks for the comment petit_pablo ...... but why would the expansion vessel suddenly need recharging immediately after a BG maintenance visit? It's been working fine all year.

 

[slapper]

Cos the BG bloke didnt know what he was doing,he didnt have his laptop.