Loud Banging Boiler

[mozzo]

I have a Ravenheat Combi.

When the boiler starts up from cold, after about 10 secs, it starts to produce a very loud banging (boiling water). It then shuts off and steam vents from the pressure relief valve (the system pressure remains reasonably stable though at around 1.5 bar).

After about 3 mins, the system automatically restarts and runs faultlessly.

Any ideas?

 

[kevplumb]

sticky pump

 

[mozzo]

Thanks Kev

Is that for sure do you reckon?

Is it serviceable or is it a replacement job?

 

[kevplumb]

undo the screw in the middle and try spinning the shaft with a screw driver

not sure but its a good place to start if the boiler is banging the water aint moving

might be worth making sure the auto air vent is open

 

[Hicko]

I,d get that pessure gauge checked to if it stays at 1.5 bar whilst the p.r.v is a blowing

 

[mozzo]

Sorry, misled you a bit.

The pressure gauge does decrease when the PRV opens.

Anyway, just to let you know, the problem was indeed the pump. Replaced and now works fine.

Many thanks