I need boiler help please.

[DextersMistress]

Been having problems with the boiler since we started using the heating frequently in the last few weeks. (Only bought house this summer, no problem with hot water)

It basically keeps losing water pressure, usually just as the heating comes on. This is accompanied by horrendous knocking, banging and hissing noises. The pressure is empty and need refilling probably every other day but the heating coming on knocks the boiler off 4-5 times a day and we have to hold the flashing fault button down to get it back on.

It now doesn't seem to want to come back on at all, despite the pressure being ok. It's a Worcester junior 24i.

Have a look on the outside wall. Water is probably leaking from the pressure relief valve. You should look for a copper pipe on the outside wall that the boiler is situated on.

How many times per second does the red light flash?

Dp had a look at the pipe outside but couldn't see any drips. It's flashing once per second.

If you top up the pressure to the normal level and then run the heating does the pressure rise towards 3 bar on the gauge?

Yes it has done a few times.

I would suggest the expansion vessel is flat. This video shows how to recharge it. It's not much more difficult than pumping up a bike tyre.
m.youtube.com/watch?v=KeO2gswQQe4

The valve can be seen at the top of the appliance close to the back by the wall and your appliance requires a pressure of 0.5 bar

This should be attempted when the pressure in the boiler is at zero and let the boiler cool down too.

Thanks so much spangle. Is there any way of manually lowering the pressure? It's not on zero atm.

You could bleed a radiator and catch the water in a bucket.

Of course

Thanks again, I'll report back.

Ok, I'm back. Had an engineer out to have a look and give me a quote. He stuck a screw into the expansion vessel and said there was hardly anything coming out which means it needs replacing. Also, the pressure release valve will be shot if it's been leaking for weeks so that will also need replacing. No mention of recharging it

Is he trying it on? Said it'll cost the best part of £260.

I've changed or pumped up vessels without the need to change the prv before. Sometimes it's hard to stop them leaking.

No excuse for not pumping up the vessel though!

The parts would be £100 including vat. Some people mark up parts by up to 20% on top. That's expensive, I'd allow myself 30 minutes to do that job. 45 if I had a cup of tea!

Thanks again spangle he told me it will take 2-3 hours!

It's a quick job if the flue (large pipe to outside off the top of the boiler) exits to the left of right as you stand facing the boiler. If the flue goes straight back out the wall or there isn't a lot of clearance from the top of the boiler to the ceiling it's a bit more involved. I don't suppose you are anywhere near South London?

No, I'm up north. The flue goes out to the right, and is right next to the bathroom window so you can sit on the windowsill and work on the boiler and the pipes outside! He also said that because the vessel was behind the boiler it was too big a job to take it off and he would simply install a second one underneath and reroute the pipes.

Anyway, my lovely friends dad is going to have a look for me, he's done the job for years

I'm glad you have someone you trust. The vessel is behind the boiler but as I mentioned in the previous post with enough clearance above the boiler is really easy to change. The flue going out to the right means it could be really straight forward.

I had a feeling about him anyway tbh, and your advice before he arrived really helped