Many prospective spoiler purchases will search for a condensing boiler review. This seems like a good idea, we often review items before we purchase them. This approach presupposes that a combi boiler is like a commodity, that they are all the same and that they are all installed in the same manner. This is not the case.

Any responsible boiler installer will conduct an heating audit and heat loss assessment before recommending the size and power output of any new or replacement boiler.

A condensing boiler is a high efficiency boiler that integrates an additional heat exchanger in order that the hot waste air transfer a percentage of their contained energy to pre-heat the cold water input. If the wrong size boiler is fitted it is quite likely that this will disturb the efficiency assumptions for how the boiler will operate and you may not gain the expected benefits.

Once you have the right size boiler fitted and it is working at high efficiency, the water vapour produced in the burning action distils back into a liquid giving up the latent heat of vaporisation.

A result will be this liquid, known as condensate needs to be piped away to a waste pipe or soak away and allow it to discharge to the outside.

The boiler will be fitted on a wall and the output gases will pass through the flue. Hot water is supplied by a little recepticle tank to enable convenient and rapid hot water accessibility.

Can you suggest on the right boiler size for my home?

In earlier days boiler installers filled bigger boilers than were needed. Whilst this ensured that there was little chance of the boiler being unable to supply sufficient hot water, even in the most icy of conditions, it also meant that they were only using a piece of their heat generation capabilities, and so functioning in an ineffective mode. If you have insulated your property since the current boiler was installed in your house, it is highly likely that you will be commended to install a smaller boiler than the current one.

We advocate looking for professional advice from a CORGI recorded fitter before choosing a suitable alternate boiler.

If I get a condensing boiler should I put in large radiators?

The main driver for smaller fuel consumption from a condensing boiler results from having a bigger heat exchanger. Larger radiators would allow lower return temperatures, and so result in even better energy performance, but the additional benefit has not been regarded as cost effective, keeping in mind that the system is running at very low capacity for the bulk of the heating season. That in all likelihood remains true, though the smaller heating requirement for new build may easily mean that householders would now allow over-sized radiators more willingly.

The SEDBUK initiative looked at this, and assessed whether there required to be new considerations for condensing boilers. The decision was that they need not, and the test results for both cases share the same SEDBUK calculation.

One Response to “A condensing boiler review”

  • Judy Green:

    Thanks for the advice on the radiator sizes – my next door neighbor was advising me wrong – should have consulted an expert I guess!