How to quickly determine if a boiler is a combi

[Goldspoon]

Not knowing a lot about boilers but learning all the time...

What's the easiest way of determining if a boiler is a combi? obviously checking there is no working F&E tank is a clue but what is a simple way of just looking at one and determining... "ah... that's a combi".

 

[giblets]

A lack of hot water cylinder in the airing cupboard might give you a clue!!

 

[TicklyT]

The presence of a pressure gauge and a filling loop?

 

[mikej2005]

The presence of a pressure gauge and a filling loop?

Wouldn't a system boiler have those ? (Conventional-style boiler on a pressurised system)

 

[D_Hailsham]

Would the number of pipes be any clue?

A heat only boiler will have: gas as well as flow and return.
A combi boiler will have an extra pipe (?or more) for the HW supply.

I know that old gravity HW boilers could have separate flow and return for CH and HW, but that is fairly rare these days.

 

[Goldspoon]

Thanks all... all good pointers

 

[Softus]

Would the number of pipes be any clue?

A combi boiler will have an extra pipe (?or more) for the HW supply.

Not just one extra pipe - cold mains in; hot out; PRV outlet; condensate (if condensing).

 

[kirkgas]

a combi could have an F & E tank, we have fitted a few now with a conversion kit to save any risk when converting onto sealed system and getting a leak, a system boiler will have flow, return & gas, a combi will also have hot, cold and blow off, tell us the make and model, or check the timer, if hot water and heating it could be either (with the wrong clock) if heating only prob a combi, you could check the boiler was off and turn on the hot tap if it is a combi the boiler will light and go off as you turn the tap on and off.

 

[doitall]

A combi could also have an cylinder on a Y plan

 

[Terrywookfit]

A combi could also have an cylinder on a Y plan

Or an S plan!!

 

[Soggy_weetabix]

The presence of a pressure gauge and a filling loop?

Wouldn't a system boiler have those ? (Conventional-style boiler on a pressurised system)

Bit misguided if you combi is gravity fed. My cousins Worcester Heatslave is.

Dave

 

[gasmick2]

Try turning the hot water tap on wait for it to get hot then turn off the cold main stop tap and see if the hot wat stops coming out of the tap,,
my greenstar is on a y plan, i only use the combi hot water on my cloaks basin and the washing machine that is in the utillity room where i have fitted the boiler,, all the upstairs is on storage exept the cold on the basin
mick

 

[Soggy_weetabix]

Is this a wind up?

My 89 year old nan knows what a combi is.

Dave

 

[Corgigrouch]

You'd be amazed at how many people think that a water heater is a combi.. Even when I tell them that it is a water heater, they say "Yeah it's a combi"
Even had one mad bag get quite abusive that I refused to touch her multipoint water heater after she called me out to repair her combi

 

[Soggy_weetabix]

I prefer water heaters! Gland seals and diaphragms is all that goes wrong.
Mind you, they always leak after a repair, but its only water. You get it right...................................................................eventually!

Dave