Faulting pump me thinks...

[Pottman]

Ok I have a situation when the timer switch operates, the boiler fires up (heard and see full flame through the inspection window) however, the pump does not start (no noise and putting your hand on it no movement) there then ensues banging noises. and the boiler cuts out (back to just pilot light) a few moments later the boiler again fires up to full flame, the pump comes on and all is well apart from a few noises of air in the system.

This only happens from a cold start, manually turning on and off once the pump is up and running and all is fine.

however, leave for an hour or so and we are back to no pump till the second fire up of the boiler, after loud knocking.

Had a plumber round and he checked that the wiring is definately for the boiler and pump to come on together, eg no microswitch in the motorised value.

So he can only sumise that the pump is faulty, and requires a bit of coaxing to get going, but once running then seems to be ok, until left off for a while.

Any one got any other diagnoses? should I try taking the pump out and giving it a servicing?

or should I just replace.

If replacing, anyone got suggestions of a good replacement for the "Hill Foster Ltd" Euramo (1 - 49 watt,24 amps; 2- 70 watt, 32 amps; 3 - 90 watt, 39 amps) it;s currently in position 3.

I am loathe to replace as it's such a quiet runner, once it is running! It's just the initial knocking is waking our 10month old!

Thanks for your suggestions.

 

[tryitandsee]

Have you tried flushing your system first, it could be crud making the pump stick. Worth a try before installing new pump.

 

[fanboy]

what you8 need to knowis ,does the pump have 240v when it doesnt run if so it will need a new pump and a system clean out preferably.

 

[Pottman]

Pump and boiler are both wired to the same junction box, so can't see that the pump doesn't have 240v to it.. guess I need to remove the cover and see use an ammeter to check for current? The system was flushed, and cleaned and fernoxed about 6 months ago... so looking more and more likely a sticking pump.
Any one recommend a good replacement, I did hear that gunfoss was the fore runner in pumps?