Glow worm 30cxi keeps coming on

[jbd1]

My mum has 2 problems with this boiler, which was installed in 2005.

1, is a roaring sound which builds up to a peak and then stops. It lasts for about 10 seconds and can occur 10-20 times a day/night, whether the boiler is on or off? This only started after a service in Mar 11. Had it re-serviced in Jun 12 but nothing was found to be wrong and of course the noise didn't happen when the man was there. He said she should call out an engineer. I guess she should of but didn't. This problem is still on going but the boiler works okay (or did until problem 2) but the noise worries my mum.

2, the radiators are coming on in the middle of the day or night when the timer is off. In Jan this year, the boiler leaked. She had an aqua block (well, that's what it says on the receipt but I think it's called a hydro block) and flow switch replaced at a massive cost of £340. It's only been since then that the rads have been coming on by themselves. The boiler is in a downstairs hall way, so it's not as if it's cold. Tried getting the man back who replaced these parts but as usual he didn't want to know!

Does anyone now what's causing these problems. Obviously the noise is a concern but having the rads come on when not required is just costing money. Bet British Gas love my mum!

Thanks

 

[ianmcd]

get Glow Worm out on a fixed price repair it sounds as thought the DHW flow switch is in demand when it shouldnt be but getting any one else out will not hold any weight with BG it sounds as though your mum is due a refund but as I say BG will only listen to a manufacturers report if that

 

[jbd1]

Thanks for the reply ianmcd. As you can probably tell, i'm not very technical minded! Didn't know Glow Worm did fixed priced repairs, guess that could be a way forward. Does the DHW flow switch cause the rads to come on then? Is it the same switch as my mum has just had replaced and could it be that the switch is faulty or has been fitted wrongly? She's not going to pursue BG but just wants the problems sorted!!

 

[Murf520970]

could be a water flow swich is at fault telling the boiler there is a demand and the divertors passing to your radiators or your boiler is coming on to preheat the water & the divertor valves passing to your radiators , turn of the preheat function & see of it continues . Do the radiator pipes get hot if you run a hot tap ?

 

[Agile]

Isn't the DHW demand valve a turbine which must have a flow to make ip give an AC output?

I thought the OP meant it came on for heating!

Tony

 

[Murf520970]

just looked agile & yes its got a hall sensor , read the op first post about the first engineer fitting a flow switch & presumed it had a mechanical flow switch , & this was causing it to come on & it maybe passing to the rads . Looks like its just calling for heat to the radiators then or the dv is passing & the boilers firing for preheat

 

[jetsada]

Did you get anywhere with this issue jbd1?

I'm having similar issues with mine, in that I can hear it fire up for 10-30 seconds and then cut off, I've noticed it mainly at night but my better half has noticed it during the day also.

Can't say I've noticed the radiators but I'll try and remember to check them next time I hear it.

It was serviced last year by Glow worm as the previous owners had it on a service schedule, looking at the notes the flow sensor was replaced. It was done a little over a year ago.

 

[jbd1]

Hi jetsada

Mum had a heating engineer round last Tuesday and he has sorted out the noise problem. Apparently a part had been fitted incorrectly and the pressure wasn't stable.

With regards to the rads coming on, when there isn't a demand for heating. This is still happening! The engineer said the boiler has a built in frost stat but as it was actually quite warm today...no way should the rads be hot. She is going to call the engineer tomorrow. If she gets this sorted, I will let you know.

 

[Whitespirit66]

jetsada>>>>>> Have you got the control knob for hot water set to pre-heat. If it's pointing to the 'Eco' part of the dial, the pre-heat will come on at regular intervals. You need the pointer set to the left hand side of the dial (between approx 7 and 10 o'clock) for the hw to run without pre-heat.

 

[mcmoby69]

is there a wireless roomstat fitted to this system?

 

[jbd1]

Update.....re rads coming on

The engineer said a switch was sticking and needs to replace 2 parts. In the mean time he has turned the control knob off of eco and to the left, as you mentioned whitespirit66. This has stopped the heating coming on.

As I mentioned before, my mum has already paid out £340 to replace the hydro block and hw flow switch, when she had a massive leak in January, then £108 2 weeks ago to have the pressure sorted, which stopped the horrible noise that she kept getting. Now (different company) want to replace the actuator head and the diverter insert set at a cost of £309!!

That's a total of £667 in 4 months and the boiler only 7 1/2 yrs old!

She hasn't gone ahead yet with the last 2 parts as I'm hoping that someone on here can confirm that this all sounds correct.

I did read somewhere that Glow worm had a design fault with their hydro blocks and were refunding customers. Does anyone know if this is correct? Also should she have this extra work done or scrap the boiler for a new one?????

Many thanks

 

[Wishy14]

Was this problem ever fixed. I have this problem now. Even when no call for heating from wireless Honeywell thermostat the heating comes on. Hot or cold weather. However when I run hot tap, water runs hot and when switched off this stops the heating. Then after couple hours heating kicks in again.
Makes no difference if wireless control box green light is on or off. Only way to switch radiators/heating off is to switch off at mains or run hot water again.

I too have just paid Glow worm over £200 single fixed rate and think they replaced something called the pump block part number 2000801901

 

[incogn1t0]

jetsada>>>>>> Have you got the control knob for hot water set to pre-heat. If it's pointing to the 'Eco' part of the dial, the pre-heat will come on at regular intervals. You need the pointer set to the left hand side of the dial (between approx 7 and 10 o'clock) for the hw to run without pre-heat.

Exactly this ^^^ The other half has the same issue on her Glowworm boiler. I reckon its "on" for 45 mins every hour, even when switched off (especially annoying as its noisy and being on most of the night was causing sleep disruption). Was about to go down the whole callout route when i read the manual. (!) It was the preheat/eco setting on the water temperature gauge making it come on. Have set the water temperature dial to the left hand side of the scale (ie to about 10 o clock) as outlined in the manual, and its now fine, hasnt done it once (and its been doing it for ages). The house is empty most of the day anyway, so hot water instantly on demand isnt needed (the point of preheat according to the manual). I know that according to the manual this feature is for hot water only, but it was also heating the rads up 24 hours a day. Good luck everyone!

 

[Gas2Air]

Exactly this ^^^ The other half has the same issue on her Glowworm boiler. I reckon its "on" for 45 mins every hour, even when switched off (especially annoying as its noisy and being on most of the night was causing sleep disruption). Was about to go down the whole callout route when i read the manual. (!) It was the preheat/eco setting on the water temperature gauge making it come on. Have set the water temperature dial to the left hand side of the scale (ie to about 10 o clock) as outlined in the manual, and its now fine, hasnt done it once (and its been doing it for ages). The house is empty most of the day anyway, so hot water instantly on demand isnt needed (the point of preheat according to the manual). I know that according to the manual this feature is for hot water only, but it was also heating the rads up 24 hours a day. Good luck everyone!

You haven't fixed it. The diverter is passing. So in the summer or warmer weather running a bath you will still find the radiators coming on.