Boring/maybe stupid questions about fitting a new central heating system

[Annianni]

We're getting quotes this week for a new central heating system.
At the moment all we have is a rather old crappy boiler that heats the water.

We're debating just getting a new boiler fitted and dh doing all the pipework and radiators to save on costs (and it then means I can have the fat old style radiators that I love)

Dh has a few questions that I hope someone can answer (he used to be a builder and knows what he's doing to a certain degree)

1. What size plastic pipe do we need for the flow and return pipes between the radiators/heating system, 15 or 22?

1. What size are the in/outlets on the rads?

The boilers we're looking at are Worcester Bosch 34CDi classic, or 32CDi compact, or 36CDi compact.

There maybe more boring questions to follow :o

can't answer in detail, but we did a similar half and half job. Your first task is to get the system flushed unless you are replacing every single piece of pipe and radiator. Otherwise it a)doesn't work properly and b) invalidates the guarantee.

keep the flushing chemical/any receipts so your installer can sign off the warranty.

Thanks.
At the moment we have no radiators whatsoever.
The house had electric storage heaters when we moved in which have now been removed.

The boiler will be going in a different place, so everything will be new/done from scratch.

that's no need for a flush then!

have you done the calculations for the number/size of radiators that you will need? This will then size the boiler for you. Any extensions planned?

A ve

A ver

Stupid phone...

A very kind British Gas man came on Saturday and told us the sizes we needed for each room, along with the best places to put them and the best route for the pipes to run round the house.
he's now hounding me with phone calls even though we laughed at his estimate of 7 to 8k

A local firm came yesterday and advised us on the best boiler sizes.
We'll probably get them to fit the boiler, lay a new gas pipe and connect everything up when dh has done the messy bit.

No extensions planned, apart from knocking a wall down between the sun room and kitchen, but that won't affect anything.

We just had our whole system replaced after finding we had an inefficient single pipe system. New boiler, 7 rads and heated towel rail. I'm afraid I just left the gas fitters to it so can't answer your questions but it only took 2 days for them to do the lot. Then a couple of hours testing on the 3rd day, and this with copper pipes and soldered joints as DH doesnt trust plastic joints not to leak
I found the whole thing much less stressful than the electrical rewire last year - DH did that half and half with a semi skilled electrician. it took about 3 weeks and drove me crackers... and I'm still waiting for him to fill in the cable runs (whilst hoping newly crawling baby doesn't decide to take an interest in the exposed wires).

oh, the quotes we got for heating were £3-5000. all local firms as British gas is notoriously expensive.

We're exp

We're expecting the local firm to be around 5000. We need 10 radiators over 3 floors (converted the attic)

We only got BG round to find out where things should go etc.
I knew they'd want silly money for doing the job.