Strange greenstar 28i junior fault

[zeebeedee]

Customer complaining heating would only stay on for 10 mins. Boiler fired for ht/hw and worked fine. Pressure would rise to over 2 bar and the burner would knock itself off. No lockout.

Thermistors in range. Expansion vessel ok and flexi connecting it. Pump ok.

Heres the strange part , the boiler wouldn't attempt to fire for ht/hw again until the pressure dropped.

Im im convinced its overheating due to a internal blockage. Back tomorrow for a flush.

Anyone seen this before?

 

[Leo21]

Can you run it with the sensors out of there pockets to test?

 

[Nostrum]

These don't have a water pressure switch so must be a circulation problem I would say? Not wildly over gassed is it?

 

[zeebeedee]

Can you run it with the sensors out of there pockets to test?

What's your thinking there?

 

[zeebeedee]

These don't have a water pressure switch so must be a circulation problem I would say? Not wildly over gassed is it?

No gas rating/Fga fine

 

[Leo21]

What's your thinking there?

With the sensors not being able to "sense" you'll be able to see of it carries on firing. If it gets mad hot hot it'll make some horrible noises, so blockage. If it fires and runs sweet, it's the señsor/sensors.