Replacing Baxi Back Boiler with Combi

[GCarnegi]

I am hoping to get a heating engineer to replace my Baxi back boiler with a combi boiler in the opposite side of the house - there are H/C pipes there so he says it should not be a problem.

The reason I want the combi is that I used to have one in my old flat and it gave me great instant hw without having to have it switched on for an hour or so before hand - which is what I do with the baxi. The boiler needs replacing anyway as it's about 15-20 yrs old.

Out of interest will this also make the HW tank in our loft redundant?

I also want to know if it will cause problems with my shower unit. I installed a new upstairs bathroom about 8mths ago and fitted a lovely Aqualisa shower with an integral pump (to be used with gravity fed systems). There was another unit available which was designed for pumped systems having no integral pump.

Does installing a combi-boiler 2 floors below (shower fitted at loft level feeding bathroom below) constitute a "pumped" system - will I have to replace my gravity fed shower unit?

Does it depend on the actual model of boiler we choose? The engineer said we'd need about 32kW for our 2 bedroom (8-10 radiator) house.

Out of interest we may be considering extending in the next year or so (but may not) with a loft conversion and third large bedroom above garage - so should we go for a bigger boiler just in case? Is this a false economy? I just like to think ahead...

thanks
Guy

 

[EliteHeat]

I am hoping to get a heating engineer to replace my Baxi back boiler with a combi boiler in the opposite side of the house - there are H/C pipes there so he says it should not be a problem.

The reason I want the combi is that I used to have one in my old flat and it gave me great instant hw without having to have it switched on for an hour or so before hand - which is what I do with the baxi. The boiler needs replacing anyway as it's about 15-20 yrs old.

Out of interest will this also make the HW tank in our loft redundant?

Yes

I also want to know if it will cause problems with my shower unit. I installed a new upstairs bathroom about 8mths ago and fitted a lovely Aqualisa shower with an integral pump (to be used with gravity fed systems). There was another unit available which was designed for pumped systems having no integral pump.

You cannot have a pumped shower on a combi system

Does installing a combi-boiler 2 floors below (shower fitted at loft level feeding bathroom below) constitute a "pumped" system - will I have to replace my gravity fed shower unit?

Not if it is not pumped

Does it depend on the actual model of boiler we choose? The engineer said we'd need about 32kW for our 2 bedroom (8-10 radiator) house.

Depends on what volumes of hot water you want. 32kW is not too bad

Out of interest we may be considering extending in the next year or so (but may not) with a loft conversion and third large bedroom above garage - so should we go for a bigger boiler just in case? Is this a false economy? I just like to think ahead...

Combi boiler size is all to do with hot water - not central heating - it is easily big enough to run double your amount of rads

thanks
Guy

 

[gas4you]

Always size the combi for your hot water usage. They will all be too powwerful for your heating requirements but will modulate down to work at the heat demand needed. If you fit a Vaillant your engineer can range rate the heating side to save even more gas. I would doubt if you needed more than around 15Kw for the rads and then when you have an extension the boiler output can be increased to accomodate the extra rads.