Leaky Pump Worc24ijunior

[soundoflondon]

I have replaced all of the radiators in our ground floor 2 bed flat over the summer. In doing so I boxed in some of the pipe work in the master bedroom and the lounge.

When the weather turned cold about a month ago, I switched the heating on. In the master bedroom the noise knocking pipes started to wake my lady up when the heating came on.

As much as I have read, there are a great number of reasons why a CH pipe can knock - air, air lock, touching wood or something else, particles or gremlins. So I started to investigate and discovered that there was air in some of the rads and particularly the towel rail in the bathroom. incidentally the highest bleed valve on the system. I re pressurised the system after every bleed. This was an exercise that had to be done again and again so much so that my good lady thought that there might be a leak, but I didnt want to believe it. I attributed the build up of air to the natural creating of air coming out of solution in the newly introduced water. However, the knocking did get better for a while, but not stop completely, although this may be phycological.

I went out and purchased Fernox protector F1 and silencer F3 in the hope that these would cure the problem. But before I put them in, I found that the pressure was very low < 1 bar when the system was cold. Worried about a leak, I decided to do some more testing. I switched the boiler off on a saturday morning, put the pressure up to 3 bars and went out. A few hours later I returned to find the pressure down to 2 bars. I first thought that there was some mechanism on the boiler to expel water as a fail safe. But I found myself looking under the boiler and found crusty green pipes and a drip. I took the front of the boiler off and the inner panel to expose a little more of the boiler. I found that the pump (I think it is the pump - i went by the manual pictures) was becoming scabby and hard water deposits were forming around it. see pictures attached.

Questions;
Is this likely to be a simple pump replacement? Or just the start of the end for this boiler that maybe 8 years old?
Have I got the wrong piece of the puzzle and it is in fact a new "widget" that needs replacing and going to cost me a fortune?
The symptoms described with the knocking and air getting into the the system are nothing to do with the scabby pump in the boiler, there are larger problems somewhere else?
Something I have not thought about.

Answers on a postcard please (or below)

thanks!! View media item 69792 View media item 69791

 

[TCCHeating]

Ooh those widgets are a bloody expensive part. Nearly as expensive as the whatsits. Lets hope you dont need a new one of them

There is a mechanism to expel water on the boiler by the way. Called the prv. Check to see if anything is coming out of that. You prob dont need a new pump, you just need to cure the leaks

 

[soundoflondon]

Thanks for your response. Do you think I could use the Fernox leak sealer F4? I am not exactly sure how that stuff works, but it seems to be pretty good for small leaks.

Thanks

 

[Tibbot]

You could save your boiler for a good few years to come if you stop p*ss*ng about adding s*it to your system. The auto air vent has failed. You need this part to function. It is a pig to change on this model, but if you're not too frightened to spend some money you could have it replaced. At the same time the engineer can check and charge your expansion vessel.

 

[soundoflondon]

thanks for the advice. What is there to fail on an auto air vent? surely it just releases air. should I not worry about the fact that there is water dripping from the pump?

 

[ChrisR]

What is there to fail on an auto air vent? surely it just releases air.

Well when it releases water as well, it's failed. Scale on the sealing seat. The water runs everywhere.

Also check pressure relief pipe outside, as abpve. Pyt a plastic bag over it to see if it drips.

 

[Tibbot]

should I not worry about the fact that there is water dripping from the pump?

The pump is not leaking, the auto air vent built into the pump housing is.