Re-pressurising brand new Glow worm boiler

[parboiled]

We have just bought a brand new Glow worm Betacom4 24K less than a month ago.​

The new boiler is already losing pressure, falling from 1.3 bars to 0.5 in a little over 4 weeks.​

The GS engineer set the boiler at 68, it's been fine, running great, noticed pressure fell slower at first but has gathered speed when it went below 1 which is probably something one would expect, still no issues in regards to how hot the house gets, heating has continued to come on so far and all the radiators are very hot.​

Only other thing, maybe this will be something or nothing? We have the thermostat set at 24.5, down from 25 since it feels like a sauna if we keep it that high. Can that have something to do with the pressure coming down?​

We have been unable to find any leaks on the radiators, pipes, no wet spots on the ceiling, etc...​

Q. 1) Does loss of pressure always happen in a geometric progression
Q. 2) Should we wait until the boiler errors before re-pressurising (filling) the boiler or should we re-pressurise before it errors?
Q.3) Do we need to turn the boiler off in order to re-pressurise since it's on the thermostat, we can just turn it off when it reaches 24?​

Thank you for any help, it is most appreciated.​

 

[steadyon]

A temperature difference of half a degree isn't go to make much difference to pressure.

To answer your questions:
1. No, pressure loss per unit of time usually reduces as there is less pressure behind any leak.
2. For now, check it daily and re-pressurise as necessary. Keep a log of pressure before and after re-pressurising.
3. Re-pressurise with the boiler not running. Doesn't matter whether you turn the boiler off, or its's not running because there is no call for heat. Turning the boiler off ensures it doesn't suddenly come on.

A new boiler installation is likely to suffer some pressure loss at first as air comes out of the system. However, I wouldn't expect it to continue much beyond the first moth of active use. If it does, call the installers back.

 

[parboiled]

A temperature difference of half a degree isn't go to make much difference to pressure.

To answer your questions:
1. No, pressure loss per unit of time usually reduces as there is less pressure behind any leak.
2. For now, check it daily and re-pressurise as necessary. Keep a log of pressure before and after re-pressurising.
3. Re-pressurise with the boiler not running. Doesn't matter whether you turn the boiler off, or its's not running because there is no call for heat. Turning the boiler off ensures it doesn't suddenly come on.

A new boiler installation is likely to suffer some pressure loss at first as air comes out of the system. However, I wouldn't expect it to continue much beyond the first moth of active use. If it does, call the installers back.

Thank you so much for answering so quickly.

It's refreshing to see someone who doesn't give all the 'doom and gloom' like most.

What we meant by the 1 degree above was, our engineer guy told us to keep the thermostat at 21.5 which is around 68, since he has the boiler set to 68 and we have the thermostat at 24.5, which is around 76, figured that may have had something to do with it.

Thank you!!!!

 

[John.g]

The boiler should be topped when cold, the cause of the pressure falling rapidly after reaching 1.0 bar can be caused by a improperly set expansion vessel pre charge and filling pressure, the next time you top it up to 1.3bar? with a cold system note the pressure rise when hot. You could possibly have a leak somewhere as well but check that first or post the normal pressures between cold/hot that you have noticed.

 

[parboiled]

The boiler should be topped when cold, the cause of the pressure falling rapidly after reaching 1.0 bar can be caused by a improperly set expansion vessel pre charge and filling pressure, the next time you top it up to 1.3bar? with a cold system note the pressure rise when hot. You could possibly have a leak somewhere as well but check that first or post the normal pressures between cold/hot that you have noticed.

This kind of sucks though since it's brand new and he did all the 'checks' and said it was 'perfect', lol, which as anyone knows, even brand new 'shiny' things can have problems, just hope that's not the case. We just want it working and not bothering with it, too much going on to deal w/boilers and all their quirks.

Yeah, we know and that was the case w/our old boiler, but the new one is digital so once it fires up, it just shows the temp which rises until it reaches 68 and it's fine. Once the heater goes off that's when it shows where the bar is set to.

Thank you John!!!!

 

[John.g]

Would think that you can switch the boiler on and have the CH & DHW (if a combi) selected off to view the pressure even if its from a menu as you really need the boiler off and cold before topping up.

 

[parboiled]

Would think that you can switch the boiler on and have the CH & DHW (if a combi) selected off to view the pressure even if its from a menu as you really need the boiler off and cold before topping up.

Okay, John, hope you're still around.

After the boiler turns off, is having it off for 2 hours good before topping up or maybe 3? The rads are pretty cold after 2 hours.

What's the worse case scenario if it's not completely cool and we fill it?

Thank you.

 

[Deleted member 123817]

There's no worse case really but you get a better idea of top up amounts when done cold, two or preferably three hours would be fine.

 

[John.g]

Topping up when cold means that the top up pressure is a good reference point when you look at it now and then, say in the morning and you can easily see if its losing pressure, another plus point is that if you know what the pre charge pressure is then you will know exactly how much water you have lost, for example if you have a 10 litre E.vessel with pre charge & filling pressures of 1.0bar/1.5bar then you will have lost 2 litres in falling from 1.5bar to 1bar. it varies with the E.vessel size and the pre charge/filling pressures but generally you will have lost ~ 1.5 to 2.5 litres.

 

[parboiled]

Topping up when cold means that the top up pressure is a good reference point when you look at it now and then, say in the morning and you can easily see if its losing pressure, another plus point is that if you know what the pre charge pressure is then you will know exactly how much water you have lost, for example if you have a 10 litre E.vessel with pre charge & filling pressures of 1.0bar/1.5bar then you will have lost 2 litres in falling from 1.5bar to 1bar. it varies with the E.vessel size and the pre charge/filling pressures but generally you will have lost ~ 1.5 to 2.5 litres.

Thank you so much for your answers/help, John, and being there for us.

Waited 3.5 hours, it shot up, literally, in 2 seconds from 0.4-1.3. The lever was a bit tight at first. We'll keep an eye on it and of course keep a record of all activity.

 

[John.g]

I suspect the pre charge pressure may be too high, it should never be higher than 1 bar, if set to 1 bar then it should still take ~ 1.3/1.5 litres to bring it to 1.3 bar, if the pre charge pressure is set at => 1.3 bar then effectively you are running on the static head from the upstairs rads (when cold) and if no leak would expect the pressure to remain at 0.4 bar for a fairly long period.

What did the pressure rise to (from 1.3bar ) when the boiler/system was hot?. if say "only" 1.8/2 bar then you can increase the filling pressure by another 0.2/0.4 bar, if you now do this with system hot, don't exceed 2.3/2.5 bar and just observe the cold pressure when system cools down.

 

[parboiled]

I suspect the pre charge pressure may be too high, it should never be higher than 1 bar, if set to 1 bar then it should still take ~ 1.3/1.5 litres to bring it to 1.3 bar, if the pre charge pressure is set at => 1.3 bar then effectively you are running on the static head from the upstairs rads (when cold) and if no leak would expect the pressure to remain at 0.4 bar for a fairly long period.

What did the pressure rise to (from 1.3bar ) when the boiler/system was hot?. if say "only" 1.8/2 bar then you can increase the filling pressure by another 0.2/0.4 bar, if you now do this with system hot, don't exceed 2.3/2.5 bar and just observe the cold pressure when system cools down.

Hey John,

Sorry getting back to you so late.

When the boiler shuts down, it shows the bar at 1.9, remember we can only see what our guy set it at which is 68 degrees, while it's running, so, once it goes off it's usually at 1.9 bar which shoots down to 1.4 and stays there for 2 hours then it shoots to 1.3 and stays there another couple of hours unless the heater comes on sooner, it will remain at 1.3, all seems great for the time being but trust me, if anything comes up, you'll be the first to know, lol.

You're really a doll for all the help you've provided and we thank you.