Hi,

Our Glow Worm 30sxi wouldn’t fire up tonight with the pressure reading 2.0 bar.

If I open the drain valve in the garage and let some water out, the pressure will drop to 1.2 but as soon as I shut the valve it goes up to 1.8, still too much to fire (?).

I can turn the water off after opening the valve and pressure will drop to 0.5 but again as soon again the valve is closed and water back on its back up to 1.8.

I’ve tried various combinations of the above to try and ‘jump start’ it but no joy.

So, any other things to try or if its knackered what might it be and is it a diy job?

Many thanks

Simon

Pressure vessel flat?

Ummmm…

Our boiler doesn’t need the water to be constantly on. Just fill it to ~1.5bar and then close all the valves. It’s a closed loop.

Is the pilot on?

Thanks all

– I’ll have a look into the pressure vessel

– It doesn’t matter what pressure I drop it too, as soon as I close the valves the pressures goes up to 1.8.

– Yes pilot is on or I know it will fire as it did for a second when I caught it but it cut off when the pressure increased.

There isn’t a pilot on those – it’s automatic.
Sounds like you’ve left the fill loop open.
Shouldn’t matter though in theory as long as as its above 0.5bar it will light.
Make sure both ends of the fill loop (that shouldn’t be there) are closed and it should stop the issue.

I had the same issue on my boiler having left it for 3 weeks in off. Lack of pressure and air in the system prevented it from firing, took me 2.5hrs fiddling with reset, on/off settings and then topping up the water to 3bar at which time it would drain back to 1.5bar via the overflow pressure valve.
In the end it was air in the system, I bleed the main rad in the front room and pretty much instantly the boiler fired on its own.
Git, it was ferkin freezing too and having to sod about with it raised my blood pressure to about 10bar… 🙄

Mines only 9mths old too..

Thanks guys

Hammyuk, I don’t know what the fill loop is, how can check that please? ( I haven’t done anything since last night though when it was working fine).

Bikebouy, the first thing I tried was bleeding and there was no air at all, I’ll try again though after I’ve been faffing.

Is there an error code showing? Is the pressure relief valve operating – is there a discharge of steam/water through a pipe to the outside wall?

The fill loop is a link from the cold water supply into the boiler. Often involving a little bit of flexible pipe. Normally there’s a little tap to open and shut the connection.

My betting is that the tap on the fill loop has either been left open or is stuck slightly open.

The filling will most likely be a silver flexy hose, bit like a tap connector with at least 1 quarter turn plastic lever on it, located under the boiler were all the pipework enters.

Ok,

No error code showing, nothing coming out of the pipe.

I’ve found the fill loop, valve is closed (and is functioning fine) and nothing has changed there from when it was working last night.

If you drop the pressure to say .5 bar (by draining of a rad etc) shoot back up very quickly with a minimum amount of top up water from the filler loop?

Some progress, checking the filler loop must have freed something as I was when I opened the drain valve again the pressure dropped to 0. I then used the filler loop to increase the pressure to 1.5.

It still wouldn’t fire though or at least not just the heating but if I put the water on as well it fired up fine. However when I turned the water off the boiler went off and the pressure went up to a new record of 2.1???

I’ve left it on for a bit to see if the rads warm up but it looks like I’ll have to call someone tomorrow.

Ours is a vaillant, so might be completely different, but the lowest it will work at is .6 bar, at rest it’s meant to be 1 bar, and full heat is at 1.5 or so bar.

It spaffs its contents outside at 2 bar, which it kept doing last year because a tiny pipe inside was blocked by crap meaning it was over pressured.