Alde comfort issue.

[Rickent]

Are these the connectors that control the gas valve?

[MtB]

No that's the electronic ignition module. Sends the spark to light the pilot.

 

Gas valve is lower down IIRC

 

 

In fact gas valve is on the lower end of the aluminium rod in your foto!

[Rickent]

This one then.

Not had a really good look , but couldn't see any obvious signs of electrical connections. 

[MtB]

3 minutes ago, Rickent said:

This one then.

Not had a really good look , but couldn't see any obvious signs of electrical connections. 

 

That's the one!

 

That looks like it could be the type of gas valve that has the thermostat built in, and the capillary leading to the sensor phial connected directly into the gas valve. If this is right there will be no wires.

[Rickent]

Just now, Mike the Boilerman said:

 

That's the one!

 

That looks like it could be the type of gas valve that has the thermostat built in, and the capillary leading to the sensor phial connected directly into the gas valve. If this is right there will be no wires.

Ok, so to eliminate the fault you describe, a new gas valve?

I take it there is no easy way to test this with the lack of electrical connections. 

[MtB]

Okayyyyyy, yes it is. 

 

The overheat thermostat doesn't turn the gas valve OFF like I said earlier, it interrupts the thermocouple thereby extinguishing the pilot flame and main burner together when tripping. 

 

Will need a short while to think about this again, everything changes!

[MtB]

Ok. After you found the header tank had expelled a load of water, did you have to re-light the pilot light?

 

 

 

[bizzard]

Tony Matts of Foxton boat Services I believe was a leading designer of those boilers. His son Sam runs the show now I think and they have the knowlesge and I think spares for them.

[MtB]

Right, the way those combined gas valve and thermostats work, this fault sometimes develops. The thermostat turns the gas off but at an ever higher temperature for any given setting on that control knob. Do you remember what number you had it on when it boiled over?

 

And have you found the pilot flame unexpectedly gone out? Possibly several times recently?

[Rickent]

9 minutes ago, Mike the Boilerman said:

Ok. After you found the header tank had expelled a load of water, did you have to re-light the pilot light?

 

 

 

When it boiled over yesterday morning, the boiler cut out and wouldnt re light until it had cooled down.

[MtB]

 

Just now, Rickent said:

When it boiled over yesterday morning, the boiler cut out and wouldnt re light until it had cooled down.

 

Ah but what do you mean by "wouldn't re light"? 

 

The pilot was refusing to light? Or the pilot was on and the main burner refused to light?

\

 

[Rickent]

Just now, Mike the Boilerman said:

Right, the way those combined gas valve and thermostats work, this fault sometimes develops. The thermostat turns the gas off but at an ever higher temperature for any given setting on that control knob. Do you remember what number you had it on when it boiled over?

 

And have you found the pilot flame unexpectedly gone out? Possibly several times recently?

We had the temp setting on the max, as we have done for the last 5 years, not had any problems with the pilot light or the boiler cutting out .

[MtB]

As always, the devil is in the detail!!

 

[Rickent]

Just now, Mike the Boilerman said:

 

 

Ah but what do you mean by "wouldn't re light"? 

 

The pilot was refusing to light? Or the pilot was on and the main burner refused to light?

\

 

The little red light on the control box was flashing, this means that everything has gone out. 

This is the light that flashes in the morning until the boiler ignites, this also flashes when the gas runs out.

Nothing would re light until it had cooled down.

[MtB]

3 minutes ago, Rickent said:

The little red light on the control box was flashing, this means that everything has gone out. 

This is the light that flashes in the morning until the boiler ignites, this also flashes when the gas runs out.

Nothing would re light until it had cooled down.

 

Ok yes, so the overheat stat had extinguished the pilot and main burner, so we know it was definitely overheat tripping. 

 

8 minutes ago, Rickent said:

We had the temp setting on the max, as we have done for the last 5 years,

 

Good, because this suggests a workaround is available to you. Run it at about half way between min and max, and I predict the problem will go away. 

 

The common fault I see on this format of gas valve is where the alcohol in the capillary very slowly escapes over extended periods of time, leading to the gas turning OFF at an ever higher temperature as the months/years pass. I think yours is at the stage where it just about boils sometimes and the overheat stat trips. Run it at a lower temp and it will be fine for a while I suspect. Eventually the problem will return at the lower setting so turn it down some more. Once you run out of lower settings, a new gas valve will be the fix.

 

[Rickent]

11 minutes ago, Mike the Boilerman said:

 

Ok yes, so the overheat stat had extinguished the pilot and main burner, so we know it was definitely overheat tripping. 

 

 

Good, because this suggests a workaround is available to you. Run it at about half way between min and max, and I predict the problem will go away. 

 

The common fault I see on this format of gas valve is where the alcohol in the capillary very slowly escapes over extended periods of time, leading to the gas turning OFF at an ever higher temperature as the months/years pass. I think yours is at the stage where it just about boils sometimes and the overheat stat trips. Run it at a lower temp and it will be fine for a while I suspect. Eventually the problem will return at the lower setting so turn it down some more. Once you run out of lower settings, a new gas valve will be the fix.

 

Cheers for your help Mike, have been running it on a lower setting for the last couple of hours and have had no issues, this makes sense.

[David Mack]

53 minutes ago, Rickent said:

Cheers for your help Mike, have been running it on a lower setting for the last couple of hours and have had no issues, this makes sense.

When using my Alde to heat water I have never had it above half setting, and it heats a calorifier of water in about half an hour. Still warm enough for a shower next morning too.

[MtB]

15 minutes ago, David Mack said:

When using my Alde to heat water I have never had it above half setting, and it heats a calorifier of water in about half an hour. Still warm enough for a shower next morning too.

 

This suggests yours could have the same problem as the OP's. Either that or you have a very efficient cauliflower. 

 

Does it trip out if you run it set to MAX? It shouldn't, it should turn the main burner OFF at 82C.

 

 

1 hour ago, Rickent said:

Cheers for your help Mike, have been running it on a lower setting for the last couple of hours and have had no issues, this makes sense.

 

You're welcome. Now would be a really good time to start looking around for a new gas valve. Won't be long before they are discontinued, if not already.

 

 

[Rickent]

28 minutes ago, Mike the Boilerman said:

 

This suggests yours could have the same problem as the OP's. Either that or you have a very efficient cauliflower. 

 

Does it trip out if you run it set to MAX? It shouldn't, it should turn the main burner OFF at 82C.

 

 

 

You're welcome. Now would be a really good time to start looking around for a new gas valve. Won't be long before they are discontinued, if not already.

 

 

An on demand water heater may be a better option.

[David Mack]

2 hours ago, Mike the Boilerman said:

 

This suggests yours could have the same problem as the OP's. Either that or you have a very efficient cauliflower. 

 

Does it trip out if you run it set to MAX? It shouldn't, it should turn the main burner OFF at 82C.

 

Don't know, as I've never needed to try it.

And I can't now until I'm allowed to visit the boat again.

[Opener]

OK - memory not too hot so recollections a bit vague.  A couple of years ago some symptom caused me to examine the header tank - pump stopped I think.  It's difficult to examine the interior of the tank but I managed to remove a right load of crap, looking suspiciously like rust, from the interior sides and, particularly, the sump where the impeller sits.  Shudder to think what the inside of the heat exchanger or pipework look like but still operating.  Get yourself a small, long handled spoon (sundae spoooon) and get dipping.  Might be nothing to do with your probs but you never know?.

[Rickent]

Quick update, since the weekend I have been running the boiler on a lower setting and have had no problems since.

MTB was probably spot on with his diagnosis. 

[dmr]

4 minutes ago, Rickent said:

Quick update, since the weekend I have been running the boiler on a lower setting and have had no problems since.

MTB was probably spot on with his diagnosis. 

with a name like MTB that's only what I would expect., ?

 

...............Dave

[Rickent]

47 minutes ago, dmr said:

with a name like MTB that's only what I would expect., ?

 

...............Dave

He is the man..the boiler man.?

[Alan de Enfield]

50 minutes ago, dmr said:

with a name like MTB that's only what I would expect

 

O' I don't know ………………………… (it is a boating forum)

 

 

Edited April 15, 2020 by Alan de Enfield