Saunier Duval Thelia 23 Boiler Won't Ignite

[tiggerblue10]

My boiler pilot won't ignite. I tried keeping my finger pressed on the button for over 20 seconds but it doesn't ignite so no hot water or heating although I've kept my heating switched off over the last few days.

Any suggestions or is it expensive call out time.....or even new boiler time?!

[wolf63]

My boiler did that and it was caused by a faulty thermocouple (sp ?). The guy said that they don't last long.

Phone a man to check it out.

[tonyav]

Probably the gas jet ( on the pilot light ) has sooted up. Most likely needs a clean and the jet poking out with a thin piece of wire.

[tiggerblue10]

Doesn't look like I'm going to get this sorted out now as I haven't got a clue what I'm looking for. And as for a thermowotsit and poking out jet with thin piece of wire, well that's just gone right over my head! Lol

[tonyav]

Sounds like you'll be needing to get a man out to it then, tigger.

[DTCwordfan]

there's a bath or two here, tigs......get the man out.

[tiggerblue10]

My dad's come round and is connecting some water pipes to do something with the pressure.

If that doesn't work he knows a plumber who can hopefully come out tomorrow.

[Garaman]

Three usual causes - no gas (or partially blocked outlet), low water pressure, and tripped after overheating. If it has tripped after overheating you need to reset a switch which will be attached to a pipe inside the boiler. It isn't exactly easy to see as it is tiny but you can usually see the wires leading to it. Ours has tripped a couple of times when the OH left the bath running.

[bhg481]

We had this problem many years ago after I'd turned off the boiler when we went away on holiday. I thought it was the thermocouple; changed it, no change. I eventually got an engineer out who said the pilot-light jet had blocked; he cleaned it and the problem was sorted. He reckoned that when you turn off the pilot-light dust settles on it and blocks it. The remedy is to never turn it off. For the past 20 odd years that's just what I've done and never had the problem again.

[Garaman]

I might be giving you false info sorry, tig. I have just had a look at the schematic for your model and can't see an overheating switch.

[tiggerblue10]

Thanks all for your help. Getting a plumber to look at it as my dad couldn't fix the water pressure thing. The water pipe is not easy to access as there is a corner swivel unit in the way.

If I do need a new boiler does anyone have any reasonably priced recommendations please. My current boiler is around 18/19 years old. Thx

[The Builder]

Hi Tiggs. I'm not sure about this one, but most boilers don't even have a pilot light. Usually just a spark ignition.

Possibly faulty spark generator.
Or, faulty sensor that has shut off the gas supply.
Faulty circuitboard... or a whole load of things.

You're right to get someone to have a look. That's a good age for a boiler, and that make is no longer as good as it used to be.

My boilerman fits only Grant boilers (mostly where the bigger models are needed)... but in your case, he would fit Ideal boilers. I've just had an Ideal fitted in my place.

[Togo]

That model of boiler does have a pilot light, so if the pilot light is lit and the boiler will not fire.... start with the thermocouple. I am just a bit intrigued with the info that you have "kept your heating off" for the last few days. Was this with a timer or controller or do you do that by switching off the boiler and heating water with an electric immersion heater?

[Togo]

If the pilot light is out I would be asking why, and if you cannot get it to re-ignite using the spark ignition button it can only be... spark ignition faulty, pilot light tube sooted up or even burnt out, or no gas. If the pilot light is indeed burning start with the thermocouple.

[RobNorth]

Whatever you do don't get British Gas....
If possible always use the local agent for your make of boiler - they will know what they're doing and will not rip you off.
If you need to replace the boiler I would recommend Vaillant (not misspelt) I replaced my 25 year old Vaillant last year as a precaution and got a quote from Br Gas because they had an offer of half price boilers......yes it was half price but the other charges meant it was exactly DOUBLE what the Vaillant dealer subsequently charged to install the same boiler. Br Gas also wanted to sign me up to a costly service contract effective from the expiry of the 12 MONTH warranty.
The Vaillant dealer gave a TEN year warranty, confirmed by letter from the manufacturer.

[tiggerblue10]

Thanks all. At first there was no hot water but the pilot light was still lit so I I switched the button off then on again. The pilot was lit again but still no hot water. After doing this a couple of times the switch turned off then it wouldn't switch on again at all.

Togo, there is a timer on it and I can turn the heating on and off manually. It also has a summer and winter setting and as the weather is warmer at the moment I've switched the lever to the summer setting so the heating doesn't come on with the timer.

I've been looking at the Vaillant ones so will probably go for one of those.