Boiler turns off by itself

[Immyran]

Hi All,

Okay, I'll attempt to make this as brief as possible. I have a Potterton Prima F boiler, an airing cupboard and a water tank in the loft.

when the boiler comes on either for hot water or central heating, it makes some clunking noise and then it turs itself off.

I have opened the bolt on the pump and and I can manually turn the rotor with a screw driver.

Also to note that the fuse tripped on the switch which I have replaced now but still the boiler turns off after making clunking noise.

I have uploaded the video where you can hear the noise.

Does this suggest that the pump is faulty?

Any help will be appreciated.

 

[terryplumb]

Is the noise eminating from the pump ,I assume the boiler is located elsewhere ? You state "the boiler turns off after making a clunking noise" .... I assume you mean the boiler turns off after the pump makes the clunking noise .
If the noise is actually from the pump you need to replace it.

 

[Immyran]

The boiler is on the ground floor, and the airing cupboard is on the 1st floor right above the boiler.

The noise does not comes from the pump but rather from the pipes or the boiler if it makes sense. I tried to feel the pump when it was making the noise but it does not seem it was coming from it.

It sounds like there is air trapped somewhere in the pipes.

 

[terryplumb]

If those banging noises are coming from the boiler it may be kettling. Hard to determine from your video alone. The cause could be a number of things. Given the fact that a fuse had blown ,the cause of that needs to be established ,fuses blow for a reason and you would be well advised to engage an engineer to investigate.

 

[MeldrewsMate]

It's the classic clunk of a failed pump - the boiler is boiling the water inside it, and the rapidly condensing steam is causing the noise.
Your pump must be over 20 years old. It's had a good life; time to let it go.

PS your old Potty Prima/Profile has outlived its usefulness too. They're very thirsty on gas; consider replacing it with a modern boiler in the next few years.

 

[Stadan20]

Open up the bleed screw on the pump and put a screwdriver in there when there is a call for heat or hot water . If its not spinning then its the pump that is goosed

 

[Immyran]

thanks for all your replies.

Yes both the pump and the boiler are about 25 years old. The are on extended side of the house which we do not use that often, only when we have guests. I will hopefully looking to replace the boiler soon.

The current pump is 'Grundfos Selectric' UPS 15-50. Any recommendations for any make or model pump replacement?

 

[Stadan20]

https://www.screwfix.com/p/wilo-yonos-pico-25-1-6-130-glandless-circulating-pump-230v/6153x