Combi boiler air purge mode (new boiler) 10 March 2022 at 10:28PM edited 10 March 2022 at 10:31PM in In my home (includes DIY) MoneySaving 13 replies 8.5K views

Dedekind

Hello

I had a combi boiler installed a couple of months ago. Worcester Bosch Greenstar 8000. It has worked fine for the past 2 months. 

Last week suddenly I didn't have hot water. I went to see the boiler and it had an error code indicating low pressure (0.1 bar or 0.3). After a few minutes it went into air purge mode and then a little bit later everything was back to normal.. until today when it happened again.. 

I am not sure if this coincided or not with a visit from our installer a couple of weeks ago, he added a copper pipe that runs outside and bends down. And he made a few changes inside as well. It may as well be just coincidence.. in any case that pipe outside is not dripping or anything, it's dry. 

Is it time to call the warranty? 

Should probably mention that it's a sudden loss of pressure. I don't think I have a hidden tiny leak somewhere.

Bendy_House

That copper pipe will most likely be the safety discharge pipe, and if it isn't dripping, that's good - no leak from there.
Can you explain further - when your boiler pressure drops, do YOU top it up again?

Dedekind

Bendy_House said:

That copper pipe will most likely be the safety discharge pipe, and if it isn't dripping, that's good - no leak from there.
Can you explain further - when your boiler pressure drops, do YOU top it up again?

No I just stand looking at the boiler and at some point it starts filling up again on its own. Then after a few minutes it's all back to normal. 

I think the auto refilling happens when I turn the room thermostat up, so that it creates demand. But I am not 100% sure.

Bendy_House

Auto-refill, eh? (Nods slowly in wonder - these boilers are nearly sentient.)
I guess it had to happen! Mind you, how can you tell if there's a leak, if it just keeps filling up?!
Must look up the instructions for that boiler - this is the first I've heard of this.

Bendy_House

A newly-filled/installed system will have air trapped/dissolved in the new water, and this will be got rid off normally via the auto-purge and radiator bleeding. But what's happening to your system sounds more excessive, especially the large pressure drops.
I'd monitor this, and the next time it happens write down exactly what you observe, and describe it to the installer.
No harm in dropping WB an email, too, asking if it's normal. It seems weird to me.

Bendy_House

Blimey!

https://www.worcester-bosch.co.uk/professional/products/accessories/greenstar-intelligent-filling-system

Do you have an App working alongside this? Ie, will it alert you to excessive water loss?

I think, for the time being, I'd let it get on, but if it happens again I'd get in touch with the installer to ask if it's 'normal'.

Dedekind

Bendy_House said:

Blimey!

https://www.worcester-bosch.co.uk/professional/products/accessories/greenstar-intelligent-filling-system

Do you have an App working alongside this? Ie, will it alert you to excessive water loss?

I think, for the time being, I'd let it get on, but if it happens again I'd get in touch with the installer to ask if it's 'normal'.

I dont have any app myself. Will look into it.. 

If there is no dripping outside does it mean there is a big chance of a leak inside? 

I contacted the installer he will have a look soon.

Thanks!

Dedekind

Actually I dont have that intelligent filler as it is an accessory I didn't buy. Not sure then what happened.

Turned off heating a few hours ago. Pressure should be between 1 and 1.5 yet its at 0.9 or 0.8. I am manually topping up now. Let's see what happens..

Dedekind

Should manual top up take too long? It doesn't go above 0.9 after a couple of minutes filling..

Bendy_House

Yikes, something is amiss. :-(

When you manually top it up, do you hear the hisssss of passing water? If so, the pressure should be increasing.

Gulp - check that copper pipe again. You can safely rubber-band a plastic bag over it if you wish.

I wonder - two purges of air - is your EV burst? On a new boiler?! Surely not.

Anyhoo, you are getting the cove out to look - please let us know what they find

Dedekind

Actually my bad.. I can't hear anything when I pull the lever down. So it's not being filled up for some reason