Troubleshooting the Thorn Apollo 30/50B Conventional Boiler: Solutions for a Pilot Light that Keeps Going Out (2023 Update)

[Sam Plusnet]

Good assumption, since a condensing boiler is unlikely to last more than a small fraction of that time. They seem designed to fail, thus forcing you to buy an expensive replacement.

[charles]

There's also an overheat thermostat on ours

[John Rumm]

Yup unless the primary heat exchanger springs a leak most of the other bits are replaceable.

[John Rumm]

Not in my case - but then my gas usage was quite high. The old boiler was using from 30 to 33 MWh/year. The replacement is using 26 to 27.6 MWh/year. So a saving of 4 to 6 MWh/year. At prices when I swapped it that was probably around £200/year. At what I am paying now more than £600.

The boiler cost me £1,100 if I were buying that alone and doing a like for like swap[1].

With the price of gas as it is now, I could swap the boiler every couple of years and still be winning!

Depends on what you buy, how it is fitted, and how it s maintained.

I put mine in in 2012, and have in that time replaced the main HEX, and (quite recently) the PCB - so you can add on £180 for recon spares...

[1] Mine was not a like for like swap - so it is not a completely fair comparison - since we went from single heating zone Y plan setup, with vented hot water to two zone heating with weather compensation, and unvented hot water.

Also if you are paying for installation then that alters the costings quite significantly.

[alan_m]

Are most condensing boilers in the UK actually operating in the condensing mode? It has been stated that most boilers in the UK have been oversized for the property and when set to a flow temperature that would allow them to operate in condensing mode they probably are just short cycling. Just because a boiler manufacturer claims that a boiler is X% efficient it doesn't mean that its being operated in a mode that gets close to this.

My recently installed boiler came with the default flow temperature set at 75C, now a lot lower.

My previous 30 year old boiler claimed 90% efficiency BUT the figure probably ignored the gas for the constantly on pilot light and the comparison was between its low water content copper heat exchanger vs a cast iron heat exchanger.

[Sam Plusnet]

True. Never had a problem with it, so I forgot.