Combi Boiler. Okay for heating only ??

Davidtrinder

I have a small house which I'm renovating as a hobby. Water pressure is poor so I don't want a combi boiler for hot tap water (one bath and three sinks)

I'm going to use a combined heat pump / water cylinder for the hot tap water (ESP Ecocent) plus a pumped electric shower.

I need to use a small gas boiler to heat the radiators. Would an ordinary combi do the job ?? All the literature talks about them supplying instant hot water plus rads but do they care if it's rads only ??

gas4you

No they don't care if rads only, but why go to the expense of a combi?

I would suggest a small system boiler say a 12Kw version if you only want rads heated.

Pincher

A combi, is just a central heating boiler and a water heater merged into one package to save space, at the expense of complexity.
The water heater side needs to have a 30kW+ heat exchanger to give a decent shower, because it has to instantaneously heat very cold water on a winter's day. For central heating, you only need around 15kW for a small house, depending on insulation, i.e. heat loss.

So if you are not going to use the water heater function, why get a combi at all?

You should consider underfloor heating at least for the first floor.
The manifold can be connected to either the heat pump or the boiler. You can control the rooms individually, and the heat pump gives you the option of chilling as well as heating.