Drips from boiler/low pressure?

kippers

Are there are gas fitters on here that could help me?  We have a British Gas service agreement but because of coronavirus they will only come out to emergencies .  We have a Worcester Bosch combo boiler and For the last 3 weeks our boiler pressure has been going down to 0 everytime we put the heating on ( it doesn’t drop hardly anything when just the hot tap is on).  I have to top up the pressure up after each time we use the heating ( which isn’t much due to it being may).  We were trying to wait until things get back to normal but today I’ve discovered slow drips of water coming from the silver nut directly under the boiler whilst the heating is on .  I wondered if the drips could temporarily be stopped by using something I could buy easily to go round the nut just until things calm down with the virus ( the nut wont turn ).  Obviously I don’t want to tamper with the boiler as I don’t know what I’m doing but if the water stops dripping would that stop the pressure dropping or is it more complex than that?
If you look closely on the second photo you can see where the drip is coming from under the silver nut.  Thanks for any help XXX

neilmcl

That's you CH return feed by the looks of it which would explain why you're losing pressure. I don't know if you want to risk trying to give it a bit of tighten or just leave it until you get an engineer out. If you can't get British Gas to come out, which is ridiculous btw, then it may be worth getting a local gas engineer to come out instead.

kippers

neilmcl said:

That's you CH return feed by the looks of it which would explain why you're losing pressure. I don't know if you want to risk trying to give it a bit of tighten or just leave it until you get an engineer out. If you can't get British Gas to come out, which is ridiculous btw, then it may be worth getting a local gas engineer to come out instead.

thank you,....however I’ve just had a look and there is now also drips come from the white thing I turn to sort the pressure out as well? It seems it drips a little bit from the white thing when the heating isn’t on and drips from the silver thing when the heating IS on.  It doesn’t drip lots and lots, just a little bit XXX

neilmcl

Is the white filling knob fully in the off position? You wouldn't normally expect to see drips from that but you would normally get a little bit of water when you remove the filling key.

kippers

Ive tightened it up and yes that seems to have fixed the white knob, thanks

southcoastrgi

It's not the return it's the pressure relief valve, it needs replacing & I'd be checking the pressure in the expansion vessel at the same time, due to the crap design of WB boilers a lot of engineers will take the boiler off the wall to change it, if you look at the installation book it will show you to remove all of the right hand side inc the pump which is why guys prefer to remove the boiler, if there is room underneath it is possible to replace it without removing anything, which ever way it's done it's a pita, WB really aren't the best boilers in the world 

neilmcl

southcoastrgi said:

It's not the return it's the pressure relief valve, it needs replacing & I'd be checking the pressure in the expansion vessel at the same time, due to the crap design of WB boilers a lot of engineers will take the boiler off the wall to change it, if you look at the installation book it will show you to remove all of the right hand side inc the pump which is why guys prefer to remove the boiler, if there is room underneath it is possible to replace it without removing anything, which ever way it's done it's a pita, WB really aren't the best boilers in the world 

Your absolutely right, my mistake. I had a quick check on mine last night, and you're correct they are a real PITA to fix on WB boilers due the stupid location they're in.

bris

Hmm bit tricky this but the PRV may not need replacing. The reason its leaking at the pipe is because the PRV is activating in the first place. The nut has probably just never been tightened properly or there may not even be a fibre washer in there. It's probably the first time the PRV has put that pipe under pressure.

You problem will be the expansion vessel either needing re charged or replaced. You are better getting someone out to get the expansion vessel looked at before asking for the PRV to be changed. You can top up the pressure, put the heating on and see if the pressure gauge rises, once it hits 3 bar the PRV opens causing the water to enter that pipe, no water enters that pipe under normal operation with all things being well so thats not the fault. So when the heating is on watch that pressure gauge and report back.

PS I usually put an external expansion vessel on any boiler that is a PITA to replace. You can do that for half the price. I only do it where the boiler is in a cupboard or there is somewhere hidden away to fit one though.