Thorn Apollo, pilot will not light

[armyash]

Hi everyone,

Been to look at a Thorn Apollo tonight, 30/50b. The pilot will light if I hold in the gas valve button and press the ignition button but goes out as soon as the valve button is released, holding it in long enough but it doesn't want to know.

Thermocouple looks ropey.

Have tried lighting lots of times according to instructions but makes no difference.

I'm thinking thermocouple, is there anything else it could be?

Thanks

 

[ShaunCorbs]

Thermo or gas valve most likely thermo normally bell on the end if fecked

 

[armyash]

Thanks, I actually said thermo or gas valve to cust. Will give price in the morning.

 

[townfanjon]

I dont know the boiler but just check the pilot jet is not full of ****

 

[thereisawizza]

I'd change the overheat stat and leads at the same time as the t/c, can also be the gas valve (normally a green button so very old). Go down the thermocouple and o/h stat rout first, then tell them to get rid of the old boiler!!!

 

[mfgs]

Good shout about the overheat stat, think it interrupts the thermocouple. I haven't seen one of these boilers in a few years though

 

[thereisawizza]

Good shout about the overheat stat, think it interrupts the thermocouple. I haven't seen one of these boilers in a few years though

Yup, good in their time but need to be in the bin now...... Had a massive shock off of one once when I bridged out the pump stat with the back of my hand!!!

 

[armyash]

Apologies for the delay in updating, the job was postponed while the cust went away.

Ok I replaced the thermocouple yesterday, relit the boiler no problem, turned the stat up boiler fires. Waited for CH to start circulating. All fine, went on my way. Had a phone call boiler has gone out same day and won't relight.

O/h stat?

 

[Last Plumber]

Is the pump over run working?

 

[Chalked]

They have a high limit cut out on the thermocouple.

 

[Last Plumber]

If the over run stat is not working, the residual heat can cause the HLS to knock the pilot out.
If the Boiler stat is out of calibration or not working, that can do the same.
Both can be tested.

 

[armyash]

I'm going to have to pick parts up again, would I be correct in thinking I shouldn't need the gas valve?

 

[jtsplumbing]

Sometimes the old gas valve gets a bit sticky, just try flicking the green button a few times then relight but hold button in for a bit longer .

 

[armyash]

Thanks for the reply.

It's the gas valve with the round grey button.

I'm confused as the boiler would not stay alight at all. I could get the pilot to light but would go out straight away once valve button released.

Changed thermocouple, pilot lit as it should, stayed on as it should. Boiler fired up fine with heating demand, rads got hot. Then I got a phone call saying the boiler had gone out same day and cust can't relight. Going back Friday. Need to have it sorted.

 

[jtsplumbing]

Thanks for the reply.

It's the gas valve with the round grey button.

I'm confused as the boiler would not stay alight at all. I could get the pilot to light but would go out straight away once valve button released.

Changed thermocouple, pilot lit as it should, stayed on as it should. Boiler fired up fine with heating demand, rads got hot. Then I got a phone call saying the boiler had gone out same day and cust can't relight. Going back Friday. Need to have it sorted.

Do the same have had this fault with the Honeywell valve , have one that I service every year, takes a wile for pilot to stay on just hold the button in for longer, Try removing button give it a squirt with WD and push it in a few times, common valve loads around

 

[Harvest Fields]

Thanks for the reply.

It's the gas valve with the round grey button.

I'm confused as the boiler would not stay alight at all. I could get the pilot to light but would go out straight away once valve button released.

Changed thermocouple, pilot lit as it should, stayed on as it should. Boiler fired up fine with heating demand, rads got hot. Then I got a phone call saying the boiler had gone out same day and cust can't relight. Going back Friday. Need to have it sorted.

Did he thermocouple have an interrupter or not?

 

[armyash]

Hi Yes it does.

 

[Harvest Fields]

Hi Yes it does.

Will probably be the stat

 

[armyash]

It was the gas valve.

Thanks for everyone's replies.

 

[Harvest Fields]

It was the gas valve.

Thanks for everyone's replies.

Glad you got it sorted mate.