Combi v. Conventional Boiler

btr30

The higher efficiency quoted for a condensing boiler is only achieved for a short period of time in a domestic situation, probably for 20 minutes each day on cold start.
Thereafter it will operate the same as a non condensing boiler with the same effeciency, probably around 80% max.

There is virtually no payback in energy terms, but if you want to change the boiler, I would go for like for like, to keep the cylinder and immersion back up facility, and eliminae any pipework alterations.
If you use a combi with mains pressure hot water you may require to change the shower too to ensure balanced hot and cold water pressure at outlet, as current cold water will likely be fed fro CWS tank.

Nada666

++ on waiting until it is actually kaput.

++ on replacing with conventional rather than combi systems.

If your [STRIKE]wife[/STRIKE]OH of whichever gender is clamouring for a makeover then, if necessary and suitable (lots of doors and no multi-level open-plan areas), consider a fancy new multi-zone thermostat system that can be transported to your eventual replacement.

paulypost

My thanks to the latest contributors. Well, within 12 hours I think I am about to do a complete about-face and stick with my good old Ideal Mexico 2. Thanks especially to Cardew. BTW the link didn’t work but my search on the Telegraph led me to Jeff Howell’s Q&A pages. His comparison of an old boiler to a 50 yr old Rolls Royce with the potential for another 50 years and a Prius compared to the new generation of boilers with a life span of maybe 10 years tops was what finally swung it for me. The following is a quote from Jeff’s reply to a reader on 15 Jan 2015:
“So my advice to all readers is to keep existing older boilers repaired and running for as long as possible. Any minor fuel savings from a replacement modern condensing boiler would soon be cancelled out by repair costs and a short working-life expectancy.”

Cardew

paulypost wrote: »

Well, within 12 hours I think I am about to do a complete about-face and stick with my good old Ideal Mexico 2. Thanks especially to Cardew. BTW the link didn’t work but my search on the Telegraph led me to Jeff Howell’s Q&A pages. His comparison of an old boiler to a 50 yr old Rolls Royce with the potential for another 50 years and a Prius compared to the new generation of boilers with a life span of maybe 10 years tops was what finally swung it for me. The following is a quote from Jeff’s reply to a reader on 15 Jan 2015:
“So my advice to all readers is to keep existing older boilers repaired and running for as long as possible. Any minor fuel savings from a replacement modern condensing boiler would soon be cancelled out by repair costs and a short working-life expectancy.”

Several posters on MSE have boilers far older than my 26.5 year old 'youngster'.


I still have the installation and servicing manual for my Ideal Mexico and servicing consists purely of visual inspection and cleaning - not a single adjustment. In fact the only adjustment on the boiler is the size of the pilot flame.

wildbri

I installed my Gloworm standard heat only boiler 40 years and 5 months ago and its still working, only had a gas cut off valve in all those years, its just a big lump of cast iron with a burner and thermostat very little to go wrong. the energy used to make a modern boiler with its stainless steel heat exchanger, fans, pump, timers and printed circuit boards which cost £300 to replace must be huge. Simpler the better I say, regards bri