pressure drops to zero every few hours

[cheekychopsmum]

I have to keep topping up with water to 2.0 bars as keeps dropping to zero after approx 2 hours. no apparant leaks.
What should i do? what happens if left overnight with low pressure?

Also see earlier posting re Vailliant Boiler

 

[adlplumbing]

check the pipe that goes outside and see if it dripping aka blow off

 

[cheekychopsmum]

check the pipe that goes outside and see if it dripping aka blow off

Yes it's dripping outside, after filling again it droped to zero within a few mins?

 

[Burnerman]

Ask someone to replace the pressure relief valve (PRV) for you
John

 

[Diyisfun]

Ask someone to replace the pressure relief valve (PRV) for you
John

Shouldnt this be get someone to check the system.
Isnt the prv just doing what its supposed to do if there is a fault. Yes I suppose they can go wrong.
Im not a plumber

======
To me this is like when you ask someone about a warning light on a car & they say ignor it, its there for a reason.

 

[Burnerman]

Absolutely fair comment old chap
John

 

[Diyisfun]

Absolutely fair comment old chap
John

Thanks for that...its nice to get someone who puts there hands up

 

[cheekychopsmum]

Absolutely fair comment old chap
John

Thanks for that...its nice to get someone who puts there hands up

Thanks for your comments, very useful.
Hvae just checked all rads for leaks (all OK) as water coming out of pipe as soon as it's filled, a suggestion is that it could be the expansion vessel! as it's an older boiler, may not be able to get part, and would have to remove from wall. Been advised may as well rplace boiler as could be just as expensive if i start replacing parts.

 

[Burnerman]

The expansion vessel could be at fault - if its full of water rather than air on one side of the diaphragm and water on the other...however there's no need to scrap the boiler for this bit alone, as a new EV can be put into the central heating return pipe at a convenient place.
John

 

[cheekychopsmum]

The expansion vessel could be at fault - if its full of water rather than air on one side of the diaphragm and water on the other...however there's no need to scrap the boiler for this bit alone, as a new EV can be put into the central heating return pipe at a convenient place.
John

Thanks for your feed back, i'm waiting for another opinion from an engineer, but looks like i'll go for the EV replacement initially and see how it goes.

 

[Burnerman]

Lets know how it goes!
John

 

[cheekychopsmum]

Thanks John,

Another engineer recommeded renewing and not to replace valve. So we're going to do that. Unfortunatley with it being christmas, have to wait till 28th for it to be done. Just keeping fingers crossed it hold out till then (keep topping it up) and we don't get a cold christmas! With snow outside, it's not looking likely

 

[Burnerman]

Replacing the PRV will sort this one I think - but as the pressure will be off the boiler its a good chance to check the welfare and pressure of the EV at the same time.
Until then, keep topping things up, look for freezing water outside and hopefully all will be ok.
Happy and warm Christmas!
John