Central heating won't come on

kuepper

Not used Glow-worm 30cxi for many months and after switching on via thermostat after allowing 20 mins or so the rads weren't much warmer than room temperature but had obviously received some heat. I bled them and only a little air in one of them. Then realised boiler wasn't firing but it still does for hot water alone. Is it likely a problem in the boiler or in the thermostat, can't think of anything else.

sourpuss2021

Pressure is too low?   Can you repressurise the boiler by turning the lever of the filling loop?  You'll hear an immediate woosh sound.

Gavin83

I’d also suggest it’s low pressure. Is there a pressure gauge on the boiler or any error codes?

Gavin83

Oh, and while I second sourpuss2021’s advice please make sure the loop is attached before you turn the taps.

another_casualty

I used to have the same model which I inherited when I purchased my flat .
Problematic , and thankfully I haven't got it now . 

Anyway , there should be a place where you can put a paper clip at the front of the unit .This resets it .
I'd say try that first. If that fails then the  try adjusting the pressure  ( 2 pressure valves under the unit . 

Keep us posted ..

kuepper

sourpuss2021 said:

Pressure is too low?   Can you repressurise the boiler by turning the lever of the filling loop?  You'll hear an immediate woosh sound.

Pressure is as recommended  1.0 bar

Section62

kuepper said:

Is it likely a problem in the boiler or in the thermostat, can't think of anything else.

Sticky/partially operating diverter valve after a long period of non-use?

(Not a DIY job though)

Bendy_House

Hi Kuepp.

That's my boiler   I'm quite offended by the disparaging comments made about its reliability by others - mine is still going strong, and there's at least one part that hasn't yet been replaced :-(

What type of room thermostat do you have - make and model, please? Is there just one heating zone? Ie, only one room 'stat?

When you look at the boiler in its standby state, it shows the pressure, which in your case is a healthy 1bar. And whenever you turn on a hot tap, the reading presumably stays the same, but the boiler bursts into life and the green 'burner' light comes on? Cool. Ok, from the standby position, what happens - if anything - when you just turn up your room stat? Is there any noise at all? Any click? Whirr? Anything? Does the pressure gauge reading change to anything (it should do, to 'temp')? Or does it remain 'deed'?

kuepper

Bendy_House said:

Hi Kuepp.

What type of room thermostat do you have - make and model, please? Is there just one heating zone? Ie, only one room 'stat?

 Ok, from the standby position, what happens - if anything - when you just turn up your room stat? Is there any noise at all? Any click? Whirr? Anything? Does the pressure gauge reading change to anything (it should do, to 'temp')? Or does it remain 'deed'?

I don't think it's the thermostat (Danfoss TP5000) now as I increased the temperature setting and the boiler kicked in with a click and a motor sound (the pump?) started in the boiler. The green light on the boiler came on but only for a few seconds then went out and the temperature that it showed  - which had started increasing - dropped down again, so all I can hear now is the motor sound I mentioned. So it seems to be something inside the boiler, it was serviced in July but only used for hot water since until tonight.

Norman_Castle

How high is your thermostat set to? Try setting it to the maximum.

another_casualty

Oops ! I have to apologies for giving the incorrect info and constructive criticism regarding the boiler 😬
The boiler I had issues with was an older model ( 30cx ..not cxi  the I makes all the difference ) 
I looked at the images and this boiler looks a much better ( and more modern ) one .
I posted for help and advice on here at the time, and obviously got lots .
Cost a lot in parts / labour etc to keep it ticking over and the 2 winters previous were not good . 

Anyway , I'll leave it there and best of luck getting it sorted 😼