Parts for Thorn Apollo boiler

[Raymundo]

Hello all,

I'm having trouble with the pump-overrun system on my old balanced-flue Apollo. The run-on time was getting longer, eventually reaching 25 minutes. I had an Interpart replacement fitted, No 402S088, although the number in the original instructions (1981) was 402S087 - the supplier said it was just updated. Run-on was 2 - 5 minutes at first, then no overrun at all. No boiler noise, but I was unhappy. My Corgi man said the thermostat must be faulty, as all the wiring checked out OK, so I got a replacement, but still no run-on, unless temperature is over 70C, then just a few minutes.
My questions are, are there different thermostats for the various models of Apollo, like the open-flue or fanned types? Is there still an 087 available? There's no application info on the packets, so any advice would be very welcome. I have tried to find parts lists online without success, but someone out there must know more than I do!

Thanks in advance for any help,

Raymundo

 

[D_Hailsham]

I'm having trouble with the pump-overrun system on my old balanced-flue Apollo. The run-on time was getting longer, eventually reaching 25 minutes.

The overrun on an Apollo is temperature controlled, so there must be some reason why it is taking so long to cool down - possibly a blockage somewhere?

Which model Apollo do you have?

 

[gas4you]

As far as I can see it is this part number THORN 4524698 THERMOSTAT PUMP OVERRUN

Parts center no 470672

This equates to the part you have got. Maybe the new part is faulty.

Fitted one about 2 weeks or so ago, didn't have any problems or call backs

 

[namsag]

Apollo pump over run stast does not sense heat within the water side of the boiler But it senses heat within the boiler casing.
If your boiler is working ok and you have wired up the new stat correctly what is the problem

 

[ChrisR]

Parts lists etc are at partsarena.com/baxi They took over Thorn.

 

[Raymundo]

Thanks for all the replies gents. My concern was that there's supposed to be some overrun, at least on "high", but I'm getting none. Still, there's no noise from the boiler when the pump stops, so maybe I should just accept that the newer type 'stat is less sensitive. I also had the high, low and limit 'stats changed, as their casings were pretty crumbly (27 years - not bad!), so it could just be that the whole temperature-range specs have been changed over the years and I'm simply catching up. I just had this idea that there might be different 'stats for the 3 different Apollos, but no-one's confirmed that, so I'll stop worrying (as if!!).

Thanks again, Raymundo

 

[namsag]

Same stats on all identified with a
brown dot and a white dot And yellow dot for limit sta tif i remember correctly.
Unusual not to get some over run on high and you would usually expect a bit of noise if boiler was upto temp and pump just stopped.

But if there is a definite change in temp from HI to LO and everything is working ok(stats not mixed up) i would not worry

 

[Raymundo]

Thanks for the reassurance Namsag.
I noticed on the first new o/run stat, which was replaced when I got no o/run, a white label with a dent in the middle. I dug through the paper and found a little brass screw-head. Looks like an adjuster to me, so maybe it is possible to change the setting. It would be a nightmare to play with though, so I'll just see how things go as they are.

Cheers, Raymundo