How much benefit from new boiler?

Fairzo

Difficult question I know. We use a lot of gas (31500 KwH annually) although our house is a reasonable size (4 bed bungalow, one in a converted loft) and SWMBO "feels the cold". Insulation of the property is quite good (including cavity fill) although there is an area above the kitchen which is not particularly well insulated as I'm not sure whether it would overheat halogen downlighters (any thoughts on that would also be welcomed).

The existing boiler is more than 15 years old, been serviced regularly, but seems to take a long time to get the rooms to a suitable temperature. It's a Ferroli combi, and we have radiator thermostats and no room stat.

Any rough ideas about how much more economic / efficient a condensing boiler might be? We had a quote for £5000 for British Gas and know we can get it cheaper than that, but really need to know that we'll get some benefit before we go to the expense.

Thanks for any information.

Cardew

Covered many times on MSE.

The concensus of opinion is never replace a working boiler for economic reasons; this thread sums it up and there are many more like this.

https://forums.moneysavingexpert.com/discussion/2686691

You can look up the efficiency of your boiler in the SEDBUK tables, but a 15 year old boiler is likely to be around 70%(my 22 year old boiler is 65%). It is possible to get a new boiler to operate at a theoretical 90% - but many engineers believe that condensing boilers rarely achieve their theoretical maximum under normal operating conditions.

What water temperature is set on your boiler? The hotter it is, the quicker rooms will warm.

Fairzo

Thanks. Don't know how I missed that previous thread as it's pretty recent.

keystone

Have your system cleaned before you do anything else. Might make a substantial difference.

Cheers

Pincher

Slow warm up could be sludge in the radiators, or heat exchanger clogging up.

Before you put Fernox F3 or similar in the system,
you should put in a Magnaclean or Fernox TF1 filter,
to prevent loosened gunk clogging up the heat exchanger. There could be a lot of gunk, so check the filter a lot.