Baxi Solo 50/4 boiler cuts out

[Telf]

I am having trouble keeping my Baxi Solo 50/4 boiler alight. It cuts out when the main boiler is working. A qualified Corgi plumber has tried several times to cure it 1st by fitting a new thermocouple which didn't fix it, and then he fitted a new gas valve but I am still having the problem intermittently. Sometimes it goes for 3 weeks and sometimes I have to relight it several times a day.
When I relight it usually it runs for a few seconds before cutting off with a loud click. If I am patient I keep trying up to 10 times or so until it finally stays on. The plumber who has serviced the boiler regularly for some years has checked the air vent to outside of the house which is OK.
Is there anything else it could be?

I realise the cut-out it is a protection device but what triggers it ? and why is it intermittent ?

My plumber says the boiler itself is fine and being on fixed income I do want to avoid high expenditure for a new boiler if possible.

 

[FiremanT]

I am having trouble keeping my Baxi Solo 50/4 boiler alight. It cuts out when the main boiler is working. A qualified Corfu plumber

Thats sounds all Greek to me!

It could either be a dirty pilot, faulty overheat stat or possibly a loose connection somewhere. Is the overheatstat connected? If it is a gravity hot water system, the leads should be connected together to bypass the OH stat. If it is connected, try wriggling the wires. If it cuts out, phone your plumber and tell him what you did, and why. There could also be a faulty pump, causing intermittent poor circulartion, then overheating.

I realise the cut-out it is a protection device but what triggers it ? and why is it intermittent ?

The OH cut out merely reacts to a rise in temperature on the boiler, normally poor circulation, but you have to look for the reason for the poor circuation. But don't panic yet, these boilers can go on for ever.

 

[Telf]

FiremanT
Thanks for your quick response. I am sorry about the 'Freudian slip' (now corrected). I must have been thinking about my forthcoming holiday there.
The pump seems to be working OK (I can hear the water circulating and feel the slight vibrations). I am not sure about the what you mean by the 'overheat stat' though.
Is that the sensor high on the side of the boiler which has long copper pipes leading into thermostat (switch) box?

After my plumber had fitted the new gas valve he checked the cables from the the thermostat box to the gas valve and re-attached them (at the gas valve end) and wiggling them doesn't seem to cause cutting out.

Today the problem seems worse and I cannot get the boiler to run for more than a few seconds. It must cut out before there is any real heat to trigger it and certainly before the water in gets hot.

I hate to ask but could this be a faulty gas valve ? It is only 6 months old.

 

[FiremanT]

http://www.partsarena.co.uk/baxi/System/DATA/Dx/DS1/installation/2188/I03-2188/I03-2188.htm

Scroll to page 21, and the OH stat is pictured top left. The sensor phial goes into the boiler alongside the thermostst phial. Anyway, the device is a bit hard to see because it is behind the gas valve. If you don't know what it is, yoiu probably havent reset it, so it hasn't tripped!

It can sometimes be erattic and cause nuisance drop outs, and I would put my cash on this. Under CERTAIN circumstances,it can be over ridden, sometimes permanently, but they don't cost a huge amount, ((£35 ish) so is probably worth changing. Your RGI should really have looked at this, but it is sometimes unfair to 2nd guess a colleague.

 

[gas112]

Does the pilot stay on if there is no demand for the main burner?

 

[Telf]

FiremanT
The OH stat must be inside the main thermostat black box on my model. There are 2 small dia cables running from this box to the gas valve and also the manual reset button is on the back of the black box.
On 2 occasions I caused a cut-out by wiggling these wires but usually that has no effect.
I would add that the reset button is still in the depressed position so obviously doesn't jump out when the boiler cuts off. I suspect you are right in that the fault lies in this part of the electrics.

Gas112
Yesterday when trying to light the boiler, yes it DID cut out once while only the pilot was alight but really I don't know the answer to your question. The pilot light is always out when I look, but I only happen to look if we notice the radiators are cold when they should be warm (so the boiler has already cut-off). I will check it more often. All I can say is that now the boiler sometimes cuts out literally only a second or so after the burners light up.

 

[Agile]

Unforunately Fireman is advising you to open the boiler and tamper with the combustion safety devices. Thats against forum rules.

Your plumber is obviously out of his depth with even a very simple boiler.

You need a boiler engineer with an electronic test meter. It seems it did not need a new gas valve, just a new engineer!

Tony

 

[Telf]

I don't see that FiremanT is in any way advising me to 'tamper with the combustion safety devices' but merely explaining how the devices work and where they are, which is what I asked.
If I do decide to try another heating engineer I like to have a bit of knowledge to avoid becoming a victim for 'Rogue Traders' !

So thanks FiremanT. Your responses to my query are much appreciated and helpful.

 

[FiremanT]

[quote="Agile";p="2380689"]Unforunately Fireman is advising you to open the boiler and tamper with the combustion safety devices. Thats against forum rules.

Er, no I'm not.
In fact, I was very careful not to do so! Unless you can elucidate.

Your plumber is obviously out of his depth with even a very simple boiler.

Possibly, but as I said, it's not always fair to 2nd guess the guy on th job.

 

[ghopper]

Hi Telf

Did you manage to resolve this. I have exactly the same issue with a Baxi WM51 in that the pilot will stay lit all day, but once the boiler fires it will cut off after anything between 15 and 45 seconds.

We had to have the gas cut off for some work outside the house and they have fitted a new pipe to the house. When we relit the pilot after the work the problem has begun. The water boiler and other gas services seem fine.

If you could let me know how you got on that would be great.

G

 

[Telf]

ghopper

I am on holiday now will have to proced further with the problem next week when I return home. I will try to remember to report back. All I can say is that for a few days before we left the boiler managed to stay alight ..... fingers still crossed !!

It has been an intermittent problem before we went with long periods of being OK.

 

[ghopper]

Thanks Telf, will be interested to see how the boiler goes on.

thanks again

G

 

[sooey]

You have much to learn glasshoppa.....

Some muck's got into your pilot, get someone out to give it a good service.

 

[ghopper]

Thanks sooey, appreciate your quick reply. Out of curiosity then why does that make the boiler cut off?

 

[sooey]

I could tell you...but then I'd have to kill you.