New boiler??? Where do I start?

scurr

Please help! We have a hot water tank and a 20 year old boiler which is being very temperamental. I'm trying to learn a bit about what I actually need before I start making a fool of myself talking to plumbers so if anyone can tell me what I should be looking for in a good combi boiler I'd be very grateful.

penrhyn

It is not necessary to have a Combination Boiler, it may be less disruptive if you have a heat only boiler.

Like this: http://www.baxi.co.uk/products/baxi-solo-he.htm

Of course they also do Combis, we had one of these fitted a few years ago:

http://www.baxi.co.uk/products/baxicombi105.htm only B rated though

Possetjohn

If you have decided you want a combi boiler, then the following things are important.

Building regs mean you have to fit a high efficiency condensing boiler unless it is "impractical to do so"! Unlikely these days

You need a high enough mains water pressure (summer & winter)

The Boiler rating is normally set by the direct hot water capacity (heating water from the mains, at this time of year 1 or 2 °C) to 50-60°C. There is normally plenty of capacity for runing the heating.

An older open system (expansion & Cold water tanks in the loft) will need significant changes and a chemical clean or powerflush before installing a new boiler. This has cost implications.

Depending on the conditions of the radiators and pipework these may or may not need replacing. The reason for this a modern combi boiler maintains the system under pressure (typically 1.5 to 2 bar when hot). Any minor leaks will be much worse and the boiler will not start if the pressure is too low. Having said that I had this type of change 15 months ago and have had no problems with the old piping and radiators.

A magnetic filter system such as the magnaflow is recommended to prevent iron oxide sludge blocking the heat exchanger of the new boiler

Valliant and Viessman boilers are good. Worcester Bosch are supposed to be good but there have been a lot of problems with freezing condensate pipes in the last month.

Some links to look at
http://www.gasboilerguide.co.uk/
http://www.energysavingtrust.org.uk/Home-improvements-and-products/Heating-and-hot-water?gclid=COiztozUpJ8CFeZr4wodzVYzJw

You will need a central thermostat which shuts off the boiler when the required temperature is reached and thermostatic valves on most of the radiators are highly recommended.

As Pehnryn says you do not have to have a combi and a modern condensing system boiler can be used to heat the existing hot water tank

scurr

Thanks for all the info - I thought all boilers now were combis - so now I've got research in 2 different directions!!

I'll keep working on it but meanwhile anyone have any guidance of costs of different options?

penrhyn

Cost us £2500 to have a conventional boiler replaced by a Baxi Combi including an RF programmable thermostat and an extra radiator.. The size of the gas feed pipe had to be increased as well.

Premier_2

scurr wrote: »

Thanks for all the info - I thought all boilers now were combis - ...

Perhaps you are confusing a condensing boiler with a combination boiler?

C_Mababejive

Get your old boiler fixed?? make/model ??