Powermax 155 only working at 2.5 bar and above!!!!

[mitzmillion]

Hi, I am having problems finding the source of the problem, 6 months ago the pressure kept dropping so expansion tank was changed, which helped, since then the boiler will only fire when it is above 2.5bar, when it drops to 1.5bar it just locks out, and ideas any one!!!!!

 

[45yearsagasman]

Suspect a faulty water pressure / level sensor. Your gauge may be faulty.
Ask yourself, why is the pressure dropping?

 

[adlplumbing]

proably as the prv passes when heating goes on as expasion will go over or near three bar

 

[Onetap]

Hi, I am having problems finding the source of the problem, 6 months ago the pressure kept dropping so expansion tank was changed, which helped, since then the boiler will only fire when it is above 2.5bar, when it drops to 1.5bar it just locks out, and ideas any one!!!!!

There's an informative site here that may help;

http://www.powermax-repairs.co.uk/

See No 5, "Pressure gauge falls to zero......."

 

[mitzmillion]

The problems with the dropping pressure were resolved when the expansion tank was replaced, the problem now is the boiler will only fire at 2,5 bar and above so maybe the fault does lie with water pressure / level sensor,

Thanks for the replies!!

 

[Onetap]

The problems with the dropping pressure were resolved when the expansion tank was replaced, the problem now is the boiler will only fire at 2,5 bar and above so maybe the fault does lie with water pressure / level sensor.

There is no pressure sensor; the cut-out is the level sensor in the brass chamber on top of the boiler.

PS Have you loosened the cap on the automatic air vent, to release any trapped air? Otherwise the AAV is possibly knackered, as the link says. Tighten the cap after use.