Typical central heating installation costs

[ChrisJ]

We've got a 3 bed house which is having another bed and bathroom added in the loft along with a new combi boiler to replace the original one we have. All the current radiators are on microbore. The plumber recommended redoing the whole system to 15mm (and 22mm presumably). We've not decorated anywhere yet but are planning to start once the loft is complete. Out of the 10 radiators we already have we want to replace the bathroom one (for a towel radiator), and a dining room and bedroom one to provide access to a conservatory and for a juliet balcony and maybe a lounge one to allow us more flexibility in posisitoning furniture (like sofas and wooden furniture that dosn't like to be against a readiator). As we are about to start redecorating throughout we don't want to get to the end and then have to mess it all up to replace the rads afterwards.

My questions are :

1) Is micro bore really that bad? My parents have just had a new house built and that seems to use microbore to the radiators. Most of the pipes (their new house and ours) seem to be buried in the walls. Will this make it more awkward? 2) Considering we are swapping nearly half of the existing rads anyway (and having another 3 new ones added in the loft conversion as well) would it be a huge difference to a) swap all the existing ones b) move away from microbore whilst we are at it?

The current system was installed with the house around 12 years ago. The floors are made from chipboard sheets.

I've googled for "central heating installation costs" but came up with nothing that gives me an idea of how much this might cost.

Any comments welcome.

[Andy Hall]

Microbore is perfectly fine provided that the system is designed properly to use it. We are talking about calculating heat loss for the rooms, sizing radiators and calculating flow rates and pipe sizes. All of this can be done in free software from the radiator manufacturers or on a spreadsheet.

It's reasonably easy to bury 8 or 10mm pipes in walls or behind plasterboard.

With 15mm, there is enough water carrying capacity to deliver about

6kW over reasonable house distances and it's something less for the installer to worry his brain about. Hiding it is rather harder.

The main thing is the pipework involved and running of it. I suspect that if you want a job with pipes well hidden, the cost will start to increase a lot.

This makes it harder to install new pipes under the floor.

Certainly avoid British Gas because their price point will generally be 150-200% more than a local installer. Often they subcontract to a local installer anyway.

If you are going for a condensing boiler (and in most cases this is a requirement now) then the system can be designed with radiator temperatures and temperature drops less than that of a traditional system. The radiators will run cooler (but need to be larger or be double where single would have been used). THe boiler will run more efficiently as well and have lower running costs.

Not all installers are aware that this can be done. For some it's easier to just bung in what they are used to and use large pipe sizes so that they don't have to do the sums.

I would shop around.

[Anna Kettle]

According to my local plumbers merchant, the bad thing about microbore, or indeed anybore other than 15mm, is the price of the kit

Anna

[Andy Hall]

No, another old wive's tale.

(Careful because you might be going to the one where Drivel works)

Looking at the BES web site:

15mm copper tube is £2.49 for 3m 8mm is £5.42 for 10m

Fittings are slightly more expensive at list price in 8mm because you can buy 15mm ones in bulk packs. However, with a bulk purchase of materials, a supplier can be squeezed. Also, fewer fittings are required anyway because the pipe is easily bent and threaded through places.

Radiator valves are the same price.

Manifolds can be a brass insert to a 22mm pipe which will accept 4x 8 or 10mm tubes and are soldered up as end feed capillary. Cost 65p each. There are more expensive ones that have rows of compression type, but these are not necessary.

[John]

Not exactly an answer to your question (but then again, no-one is likely to have the exact set-up as you so any prices offered can only be ballpark figures) but we're renovating a two bedroom (originally 3 bedroom no bathroom, so my dad converted a bedroom into a bathroom when they moved in in 1956) victorian mid-terraced that has never had central heating before. A local CORGI heating engineer quoted as follows:

• To remove 3 old gas fires, make good, then supply and fit 2 new gas fires

• To install complete new CH system - Alpha CD32C condensing boiler and 7 radiators

• To install gas hob

• To do all "wet" plumbing in kitchen, ie, sink, plumb for washing machine etc.

• To supply and fit new toilet and wash basin in bathroom (keeping existing bath 'cos it's a huge cast iron beastie - just paid £200 to have it resurfaced and it's brilliant, but I digress)

• To carry out Landlords Safety Certificate work on the four gas appliances

• To plumb in an electric shower (so that future tenants have still got something to use if the gas goes off for any reason).

For that he quoted (and actually stuck to) £3612 and did a superb, first-rate job (this is in Preston, Lancashire, BTW).

John. PS The Alpha boiler has a 3-year manufacturers warranty and Alpha are now asking installers to go and do a service just before the warranty runs out so that in the unlikely event that anything is wrong (or even just something that may be "on it's way out") it'll be picked up and sorted by Alpha before the warranty runs out and the consumer - although nothing is 100% certain, of course, - shouldn't have to worry about something breaking down two days out of warranty.