combi boiler

[evertonsue]

What is a combi boiler and how is it different from other boilers?

[ianess]

A combi (or combination boiler) is a compact and highly efficient unit giving all the heating and hot water you need, with significant savings on running and installation costs.

Unlike a conventional heating and hot water system, a combi boiler system does not store domestic hot water. It heats water directly from the cold mains - as you use it. There's no hot water cylinder, no tank in the loft (and so less risk of freezing and flooding), and none of the connecting pipework. So you not only save space, but also reduce hot water costs - which can account for up to 60% of a typical domestic fuel bill.

 
 
A combi also supplies hot water at mains pressure, giving you exhilarating power showering without the need for a pump. And as, on average, a shower uses considerably less water than a typical bath, the savings on hot water costs and water consumption can be significant. 

[tetherend]

Our combi boiler is in the loft, which would explain why we have to wait for ages before any warm water comes to the taps downstairs, and possibly why there is little power in the flow.

[flaming]

I have a Potterton combi.  (Potterton have amalgamated with Baxi)  It is the only option in my flat.  Water in the pipes is mains only.  My flat is a duplex 2nd and 3rd floors. My third floor is under the flat roof.  When I moved in I was having a lot of problems with the hot water; once work (expensive) had been done to the boiler things are excellent. My kitchen is on the second floor, the bathroom - with boiler cupboard are on the third.  I get very good hot water at a good pressure in the kitchen (heated water coming down) so I feel that tetherend might have boiler probs. too.

The hot water takes la bit longer to come through if the heating is off.   I believe the new condenser boilers are mandatory now, and they are a bit more expensive but I am told they are very efficient and make even more savings over a year.  I see a previous resident had coupled up a small hot water storage cylinder, but I haven't found a replacement necessary.  So long as the boiler is OK you never run out of hot water.