central heating installation

[Fred]

Hello,

We have been house hunting and one of the houses does not have any central heating fitted.

I was thinking if we bought that house, I could fit the water side of the CH myself and get a professional to do the fuel side of things.

I suppose it's a big job because although the plumbing should be simple enough, the problem is lifting all the carpets and floorboards etc. to lay the pipes beneath.

If I plan in advance and run the pipes parallel to the joists that might help but I think that cutting the joists will be unavoidable.

Part of me thinks if a job's worth doing, it's worth doing properly but OTOH I wonder whether I could make things easier for myself by boxing some pipe work above floor level. What would you do?

Now the second problem: this house is in a village without a gas supply. So I think we would have three choices:

1. use oil
2. use gas bottles
3. get a gas tank

I presume that 1 or 3 would be expensive. Is one cheaper than the other to install?

I think with gas you are tied in to a particular supplier afterwards but OTOH I think an oil boiler costs more to install so there are pros and cons to both.

I think gas bottles might be cheaper in the short term but how long do they last? Obviously this depends how long and how hot I run the CH.

Or would you recommend we stick with the storage heaters they use at present?

Finally, would I need a gas boiler modified for bottled/tanked gas and if so, what is involved?

Thanks.

[John Rumm]

Indeed, or do it all yourself.

Yup, like wiring, the bulk of the work is actually the creating access and making good after.

Almost certainly. You can cheat a little these days with plastic pipe, but you will still need to cross joists at some point. The plastic is at least easier to thread through holes drilled through the middle of the joists though, to save needing to notch them.

Depends on how much stuff needs to be moved in each room. Also are your floors downstairs solid or suspended?

Cheapest would be 1, then 3, and 2 the most expensive to run. 2 would be the cheapest to install, with 1 and 3 about equal in cost.

I expect install costs would be quickly lost in the grand scheme of things. So go with the cheapest running cost.

For running a hob they last well, not so sure about on a boiler.

Probably not. Oil ought to be a little cheaper but far more controllable.

IIUC, usually different injectors/jets need to be fitted. This is often a low cost conversion on many boilers.

[Owain]

You can cut down the disruption by only running main pipes above the ground floor ceiling / below the first floor, and doing vertical drops down to ground floor radiators. This can be fairly inconspicuous if done in corners or behind curtain drops.

Microbore can be threaded through small spaces more easily.

Oil is probably the way to go, more competition with suppliers. You may need planning permission to site a tank though, and there are Building Regs restrictions on where you can put it. A larger tank allows you to buy more oil in summer when it's usually a bit cheaper.

You can also get oil Agas if you're that way inclined.

In Italy it's common for gas tanks to be buried, I don't know if this is allowed here.

Depends a lot on the type of house, your lifestyle, and whether the storage heaters are adequate. Longer term, installing a proper CH system is likely to add more to the property than it costs to do.

Owain

[Calvin]

I back up what John has said.

We moved into a house with (nearly) no central heating and no gas in the village 13 years ago. At the time I had many of the same questions as you and was seriously considering installing storage heaters. I'm so glad I didn't.

Oil boilers are more expensive then gas to buy and you'll need an oil tank but the rest of the job is identical. Oil turns out to be a cheaper fuel than natural (piped) gas but slightly less convienient as you need to get oil delivered once or twice a year. Oil is far cheaper to run than either electric storage heaters or bottled gas by quite a margin.

Having installed oil fired CH myself I can tell you that it's not a particulary difficult job but it is time consuming and disruptive to the house, so best done immediately after moving in and definitely before you get the place looking good. Lifting floorboards is probably the worst bit in terms of mess and disruption. As as guide it took me a full week (days and evenings) to do a 4 bed house but that was going some and I had the house to myself during the day. That said I was using copper pipe rather than plastic which made it a lot slower and harder. Having just done my new bathroom using plastic I'd definitly use it for a full heating install if I did one now.

There are many good sources of information but the most important (other than uk.d-i-y of course) is the building regs. They are available online from the direct.gov website and although many people see them as a set of restictions you can equally well consider them a useful guide to best practice backed up with a stick. My advice is to use them as your primary source when planning your system. They cover in detail the siting and installation of an oil tank as well as the minimum controls needed to make a CH system efficient. They also tell you how big a hole you can cut in a joist are where! Manufacturers are also really good at publishing detailed guides online and all of the technical stuff like which pipe sizes are needed at various points in your system and how big a radiator to use in a particular room are easilly available.

Good luck with your house purchase.

[Owain]

And if mains gas subsequently becomes available, only the boiler needs to be replaced.

Owain

[Fred]

I've done odd-jobs with copper pipe; mainly with compression fittings. I have used push fit and end feed but I haven't mastered soldering the end feed fittings yet! I haven't use plastic pipe before.

It sounds as if it might be good for running under floor boards but how do you insulate it? Does the usual grey foam stuff fit it?

Another reply suggested micro bore. I was going to use the ubiquitous

15mm. What are the rules regarding when you can use smaller sizes?

I was going to ask about the rules regarding oil tanks but since you've told me where to find them, I'll see if I can find them myself.

Gas boilers seem to be easy to find in Screwfix, B&Q, etc. Oil boilers are not. Do they cost much more and where can I find them?

Thanks.

[Dave Liquorice]

You can do most yourself, commisioning probably needs a "qualified" person to sign of the bits of paper if you are worried about or need them.

Another thing to consider with such a major installation is the HW side and adding solar and/or woodburner to that. Possibly a heatbank with several different sources of heat.

[geoff]

In message , Fred writes

They will be badged boilers from "real" manufacturers - e.g. Wickes sell Halstead, generally cheap to buy, expensive on parts to repair

[Owain]

Microbore is usually plumbed (I was going to write wired...) with individual flow/returns to each radiator from a central manifold, although it doesn't have to be. You do usually need individual flow/returns to each radiator from the 'main pipes' (15mm or 22mm) though.

A couple of microbores will fit inside plastic electrical trunking if you need to hide it.

Owain

[John Rumm]

You could insulate it in the same way, however part of the point of a heating system is to "lose" heat into the house, so uninsulated pipes are not in general hindering this.

Flat out 15mm is limited to about 6kW - enough for a couple of large rads or a few more smaller ones. Typically you have larger main flow and return pipes that the smaller 15mm ones branch from and return to.

Microbore uses a similar concept except often with manifolds. The manifolds would be fed with larger bore pipes.

Look at any specialist boiler supplier or online plumbers merchant...

say:

[Calvin]

Plastic pipe is just wonderful. Because it's flexible you need far fewer joints than with copper and you can thread it into places. It's a little more expensive that copper, or at least the fitting are, but so much easier. The normal foam insulation works with plastic pipe and in fact because you tend to feed it through a hole drilled in the joist you can get the insulation on properly. With copper you are forced to notch the top of the joist which leaves it too close to the floorboard to fit the insulation properly so you end up having to slice part of it away.

I did my CH in 22mm for the main runs with 15mm for branches and to the rads. SInce then I've used 10mm plastic for a few jobs including a "special" heated mirror-come-radiator in my shower. If I were doing my CH now that I know a bit more I'd certainly look at the capacities of the pipes more carefully and use 10mm where possible. My guess is that most of the runs to the rads could be in 10mm, it really is very capable and so incredibly easy to use (I've just looked it up and 10mm tube can supply 2kW, 15mm=3D6kW). The way to go about it is to do a calculation for each room to determine the heat loss and hence the heat required. Google for "heat loss calculator". You can then choose a radiator for each room and you can plan your pipe layout. From the layout and heat loss you can see how much heat each section of pipe will need to carry. The capacities for various pipe sizes are published by the manufacturers so it's easy to see the smallest acceptable pipe for each section. Have a look at

Please do look up the regs before doing the jobs but as a quick guide a tank needs to be a certain distance (from memory 3m) from a wall with openings and if it's anywhere where an oil leak could get into a protected watercouse or drain it needs to be double skinned (bunded). A tank will set you back around =A3350-=A3500 plus you will need to make it a solid base to keep it happy.

Oil boilers are available from any plumbers merchants or google for them (I would never, ever, buy such a thing from B&queue or screwfix). You might like to consider a condensing type which are more efficient but will require physically bigger radiators as the water in the system is run cooler than with a convential type. One particular make, Wallstar, is popular as most of the workings fit in a (large) hole in the wall and are accessed from outside leaving just a small white "cupboard" inside the house - very neat. There are of course building regs covering where you can fit a boiler flue so you will need to survey your house to find a good place.

Hope this helps. Calvin

[The Natural Philosopher]

Not even a pro for fuel.

Yes. If the floors are nothing special consider ripping them ALL up and dong a floor re-lay.\

Also concern yourself about vertical pipe runs. If its brick or block walls you MAY need a vertical run of major pipes boxed in. Studwork walls can be hacked about to fit.

Yes. Top notching will be OK if you relay ply or chip over as a stressed skin. For floorboards its better to try and go through beam centres and use flexible pipe.

This may e a lot cheaper han copper these days - copper is alarmingly expensive.

Rip up all the floors ad replace when done. I'd probably then do UFH anyway ;-)

No, you have only one choice. Oil.

Gas is a nightmare to handle except in pipes. You need special storage. Well you do for oil too, but it's not so stringent. Its cheaper than gas too unless you are on a gas supply.

You COULD also use solid fuel.

Or indeed electricity: it may ultimately be cheaper han gs or oil if teh nuclear power stations get built.

Its about a grand to install an oil tank and its not hard to pipe up.

Not really. Oil boler ar just boilers - you need a few exta gubbins like fire detecting fuel cutouts and a filter has all.

No. They are teh worst of all possible worlds.

Don't go there. Go oil.

Budget about £10k for total installation and making good.

[The Natural Philosopher]

yes.

I hate microbore. To easily damaged for my skilss.

No they do not really cost that much more. Look under system boilers, or if you have a room where you can fit oe, a boilerhouse boiler. These come uncased. It is very mice to try ad collect all the plumbing in one place including a pressurized hot water tank. It can be worth building an outhouse for all this if the property is small.

Don't even think Combi unless its just the two of you and the house is small.

[Dave Plowman (News)]

It tends to be rather noisier than 15mm which might be an issue for some.

[Fred]

So for example, if you have a 1kW radiator and you know 10mm pipe is ok up to 2kW, you use 10mm pipe but if you have a 3kW radiator you know you have to use 15mm pipe?

I thought you had to put a wall around it if it was next to a fence to prevent fire spreading into the neighbours property?

Is it ok to DIY the oil tank and oil connections? I know there are strict rules about gas; are there not similar prohibitions on oil work?

What special precautions do you have to take with the line from oil tank to house? Does it have to be a certain depth underground? Does it have to be reinforced or within another pipe?

I will have a read of the regs. to see if they answer my questions.

Thanks.

[Fred]

What various bits of paper are required for oil installations?

Have you used solar? Is it effective in the UK? How does that fit in? Do you have an extra coil in the cylinder for the solar circuit? How much does that add to the cost?

Thanks.

[Fred]

Why would I need a pressurised hot water tank? I've only ever come across gravity fed ones before.

Thanks.

[Dave Plowman (News)]

They get round the need for a header tank so ideal for those living in little boxes who don't mind the noise and inconvenience of mains pressure water everywhere. And of course think that everywhere has good mains water pressure.

[Tony Bryer]

It may just be cost-effective if you have a south(ish) facing roof slope, use a fuel other than mains gas, and you use a reasonable amount of hot water (i.e. family not single). But for most commercial installations the numbers don't stack up ... especially if you are going to have to pay someone to clean the panel every couple of years.

I was at Interbuild last week and a Chinese manufacturer was exhibiting solar panels at just over £100 each. If the kit gets down to these prices it may yet make sense.

[Fred]

What is this? How often is it held? Is it worth going next time?