Combi, system or regular: which new boiler suits a Kirkham or Wesham home?

For most smaller homes with one bathroom, a combi is the right answer. For homes with two bathrooms and several people wanting hot water at once, a system boiler with a hot water cylinder usually is. A regular boiler, with tanks in the loft, mostly makes sense when you are keeping an older setup that already works. That is the short version. The rest of this page is the five questions I ask in every Kirkham and Wesham house before I recommend anything.

The three types, in plain English

• Combi: heats water straight from the mains as you use it. No tank, no cylinder, takes up the least space.
• System: heats a hot water cylinder, usually in an airing cupboard, but needs no tanks in the loft.
• Regular, sometimes called conventional or heat only: heats a cylinder and is fed by a cold water tank and a small expansion tank in the loft.

Question 1: how many bathrooms do you have?

This decides more than anything else. A combi serves one outlet properly at a time. Run a shower and someone turns on a hot tap downstairs, and both get less. With one bathroom that rarely matters. With a bathroom and an en suite, it starts to.

Question 2: how many people want hot water at the same time?

Two people in a one bathroom house, a combi is ideal. A family of five all trying to shower between seven and eight in the morning is a cylinder household, whatever the house looks like from outside. Be honest about the busy hour, not the average day.

Question 3: how strong is your mains water?

A combi can only deliver what the mains gives it. If your cold taps are already weak, a combi will give you a weak hot shower too. I check the flow at the kitchen tap when I come out, because it is the one thing that can rule a combi out completely, and it is not something you can tell from a form.

Question 4: do you want the space back?

Going from a regular boiler to a combi frees up the airing cupboard and clears the tanks out of the loft. That is a real benefit, and in a smaller house it can be the deciding one. But it is also the bigger job: the cylinder and tanks come out, pipework changes, and things get made good afterwards. Worth it when the household suits a combi, not worth it just to have the airing cupboard back.

Question 5: is the rest of the system in good shape?

A new boiler on old, sludged pipework will not perform the way it should. If some radiators are cold at the bottom, or the system has had a lot of leaks, that needs dealing with as part of the job. I would rather tell you that at the quote than have you find out a month after fitting.

What I do when I come out

I look at the boiler you have, where it is, the pipework, the radiators and the water pressure, and I ask how the house actually uses hot water. Then I quote in writing for the boiler that suits the house, which is not always the biggest or the most expensive one. I fit it myself, so the person who quoted it is the person doing it. If you want to understand what moves the price, I have written about what drives the cost of a new boiler, and if your current boiler is giving you heating but no hot water, it may be a repair rather than a replacement.

Kirkham is a straight run west of my Preston base along the A583, with Wesham right next door. For the full details of how I fit boilers here, see my page on getting a new boiler in Kirkham. For repairs, leaks and everything else, there is my page for a plumber in Kirkham and Wesham. Or ring me on 07949 353536 and I will come and have a look.