thermocouple dies after switch off of boiler

[unclebob1]

Good Morning,

I purchased a house back in Nov 2011, the owner kindly turned off the boiler before leaving.
I promptly restarted it later that day/next day when i got the keys and set the temperature to approx 15 degrees on thermostat so that the house wasn't cold while unoccupied.

Few days later i returned and found it cold - the boiler pilot light had gone out.

Got someone in to have a look and they replaced the thermocouple, temp was adjusted to approx 20 for normal use.

Fast forward 3 years, and the boiler was switched off again - this time for some work in the kitchen. Again it was off for most of the day. Ignited first time and stayed lit... until this morning ( 3 weeks later).
House was cold and when checking the pilot light it was out. Relit the pilot light, but it wont stay lit. When looking though the little window i can see the tip of the thermocouple which looks like it has a tiny cauliflower on the end in the shadow of the flame, ie its burst just like it did 3 years earlier.

So I'm assuming thermocouple again - someone coming to change it later today.

The boiler over the three years has been turned off for servicing etc but not for long periods. Those times it not been any issue with getting it on and staying on - and not needed to change the thermocouple.

Is this a problem with the termocouples or possibly a problem with the setup in the boiler?( its a poterton flamingo if it makes any difference).

 

[gas112]

Just that thermocouple are made cheaply now and don't last ,the actual proper Honeywell one will last longer than universals and nickel plated ones will last longer too

 

[Bosswhite]

Always been a problem with thermocouples, Leave the Boiler switched off for a length of time and they pack up when one switches the boiler back on.

 

[Agile]

Be aware that your boiler is very reliable because it is so simple, but it is not very efficient compared with current ones which would probably save about 15-25% on the gas consumption.

If your gas consumption is average, about £800 pa, then the saving will not financially justify a replacement but bear that in mind.

A few years ago the Gov offered a £400 boiler scrappage scheme for older boilers like yours to help reduce the carbon footprint.

Tony

 

[unclebob1]

Cheers for the replies - guess I'll keep a spare handy - more kitchen work/gas work due to take place over the next few weeks - last thing i want is for a replacement part not be avilable because its xmas day etc!

 

[unclebob1]

Thanks Agile,

New boiler is in the plan - currently need to move my existing kitchen out to the extension being built (bricks to DPC level going down today!), so that the new boiler and new hot water tank can be placed in position of the current cooker and fridge freezer! Hate doing major works while living in the house but it means no renting which equals money to change boiler + Tank!

 

[Dean744PiN5]

a thermocouple is a consumable item imo that should be replaced regularly at the time of service to save on a call out in the future (£10 on top of the service as opposed to £60+ repair), don't forget it is subjected to the temperature of a flame 24 hours a day 365 days a year, the poor little blighter is under a lot of stress.

 

[Agile]

Thermocouples vary a lot in their lifetime. I often see many 10 years old and still fine. Cheaper ones now probably have a shorter life span though as do those where the pilot light flame is too high.

On a service I look at them and measure the voltage out and if that is correct don't change them until they are three years old.

 

[unclebob1]

The old thermocouple attached. Seen better days.

 

[Agile]

That almost looks as if the flame is too big.

Its a balance between smaller flame and longer T/C life but with the risk of the pilot being blown out when its windy and a larger flame which will overheat it and shorten the life.

Many like the larger flame option as that will not get them blamed if it blows out and get them another job sooner!

Tony

 

[FiremanT]

A few years ago the Gov offered a £400 boiler scrappage scheme for older boilers like yours to help reduce the carbon footprint.

Tony

Seriously? BG always offer a "discount" for something, they just keep changing the name. It takes the price down from Extortionate to Expensive. Then they farm out the job to the guy who you probably got a price from, but decided to stick with the "experts"

Bit like DFS's sale finishing this weekend, it has to - another one starts Monday.

 

[picasso]

Your not on lpg are you ? (I see your in london but the boiler might not be )

 

[TCCHeating]

Seriously? BG always offer a "discount" for something, they just keep changing the name. It takes the price down from Extortionate to Expensive. Then they farm out the job to the guy who you probably got a price from, but decided to stick with the "experts"

Bit like DFS's sale finishing this weekend, it has to - another one starts Monday.

Yeh pretty sure Bg still give scrapping discount even though the scheme ended years ago. Go figure!

Bg salesmen are no different to double glazing salesmen or any other salesmen. Increase original price to take off whatever so called discount they can make up on the day. Day one in the salesman training course. But I would hope that the majority of punters are well aware of this practice in this day and age

 

[FiremanT]

maybe so, but wasn't it Courts who appeared on TV (on Mary shopping guru programme) and stopped the "massive reductions" on her advice. TGheir ads appeared saying this is £500 and never was £1000. Or something like that. Lasted about 6 months, and gone back to the "discounts."

Which suggests that the great British public is still gullible.

 

[TCCHeating]

Yep. You're right. Saw that programme as well.

Also saw a watchdog program on the likes of dfs etc. When they claim 'sofa was 1000 but now 500'. It turns out that the sofa was only 1000 for a day, or sometimes even a few hours! Turns out it is pretty much legal for them to use this con tactic. And it definately works for them as the daughter of Mr dfs lives a few miles away from me in a security guard protected massive mansion. On the road Between Linton West yorkshire and Sicklinghall North Yorkshire if anyone's interested!