Topping up boiler, how often?

[wedge69]

Probably open up a can of worms here.

How often should a combi boiler on a sealed system need topping up? I'm sure some people will say never as any sign of a pressure stop is a leak, but the Worcester Bosch website says once or twice a year is perfectly normal.

Take got example my system. Since the heating went off last year in April, I've lost a grand total of 0.1 bar (digital display). I'm going to assume that amount of water over that time is nothing to worry about and would be almost impossible to trace, and it's when you're losing that amount every day that you need to worry.

I've got the boiler being serviced next week so will ask them, but just wanted to gather thoughts here. For full disclosure I am a bit of a worrier so sometimes these things play on my mind.

 

[terryplumb]

That level of pressure loss is of no real consequence.
You only need to worry about pressure dropping regularly ,like every month/ weeks or less

 

[Jurassicspark]

0.1 bar loss of pressure in a year isn't something to worry about.

I take that you don't have inhibitor installed in your heating system?

 

[wedge69]

There is inhibitor in the system. Had some radiators replaced last year. They only put a small bottle in though and we have 16 radiators, so maybe need some more?

 

[Jurassicspark]

Litres?

 

[Johntheo5]

Probably open up a can of worms here.

How often should a combi boiler on a sealed system need topping up? I'm sure some people will say never as any sign of a pressure stop is a leak, but the Worcester Bosch website says once or twice a year is perfectly normal.

Take got example my system. Since the heating went off last year in April, I've lost a grand total of 0.1 bar (digital display). I'm going to assume that amount of water over that time is nothing to worry about and would be almost impossible to trace, and it's when you're losing that amount every day that you need to worry.

I've got the boiler being serviced next week so will ask them, but just wanted to gather thoughts here. For full disclosure I am a bit of a worrier so sometimes these things play on my mind.

To quantify it, a 10L EV with recharge/filling pressures of 1.0/1.5bar will have lost 0.33L in falling to 1.4bar, but difficult to measure 0.1bar accurately, more realistic probably to say that if it fell from 1.5bar to 1.2bar, 1.1L, say in 6 months, then maybe a worry?.
I have a OV system with a isolation valve on the F&E makeup which I keep closed and have never noticed a single drop of water making up when I open it every 3 months or so.
Edited, above

 

[wedge69]

Litres?

500ml I would guess. Was a small bottle

 

[Jurassicspark]

That's a litte amount for 16 radiators...

 

[Elkato531]

That's a litte amount for 16 radiators...

On top of what was already in there. Almost certainly fine. Don't worry people needlessly.

 

[wedge69]

Thank you all. Not having the best of times at the moment so worries come to the forefront. I know heating systems are a complex beast with a fair bit of science behind them, but I'll try and keep trying myself that a loss of 0.1 over four months is not worth worrying about. Hopefully this can help other people too.

 

[wedge69]

Just to follow up on this. Had the boiler serviced today (by Vaillant). He was a really decent guy, reassured me as all you did that a small amount of pressure loss was nothing to be too worried about. Tested the inhibitor and we didn't have enough, so there's more of that in. Also had a slight leak from the AAV so that was replaced, and the expansion vessel was recharged , so we're all good.

 

[Jurassicspark]

On top of what was already in there. Almost certainly fine. Don't worry people needlessly.

Sometimes you've got to be prudent.

 

[wedge69]

Well, the saga continues. After the service I needed to top up the boiler a little. Obviously expected this as some air would have been introduced when the boiler was drained down.

However, on Saturday morning the boiler had lost 0.3 bar. Same again Sunday morning and same again today - 0.3 everyday without the heating on.

Vaillant are going to come back out, but not until Thursday so I'm going to be topping it up until then.

No idea where the water is going. Nothing under the boiler and nothing out of the copper PRV pipe. The condensate is plumbed in so can't really inspect that. No signs of any leaking radiators (not sure how a boiler service would have affected that anyway) and no damp patches on the ceiling.

I'm just hoping it's something simple like the new AAV is faulty, but that doesn't explain where the water is going ...

 

[Johntheo5]

Thats around 3litres!.

 

[wedge69]

Yeah, so I'm struggling to understand why I can't see anything!

I'm going to stop topping it up and not use the hot water or heating until it has been looked at. At least that way I'm not adding any more water that could be leaking out.

Any thoughts on what a boiler service could have triggered? Best case I'm hoping something has just been left untightened. Worse case, running the heating caused something in the pipework to pop, but as I said, there's no obvious signs.