The house I've just bought has a conventional boiler that's reasonably recent (7 or 8 years) but they've installed the hot water tank in one of the bedrooms taking up lots of useful space. I'm wondering if I can stick a combi boiler in instead - thus doing away with all the old fashioned stuff. Any idea of costs - the house is a 3 bed semi.

Any thoughts or experience?

Vaillant may be the way to go; we've not had many problems in the last four years or so since ours was installed; I think the expansion vessel had to be changed and that's it.

The Potterton that this replaced was a nightmare; sensors, expansion vessel, leaks, circuit board poor design/failure...

Sure you can, you will have to remove the pump.

Remove the wiring for pumps, zone valve(control circuit).

Reconfigure pipe work where cylinder is fitted. Should be easy enough.

Where the new combi is fitted you will need mains water, likely 22mm gas direct to the boiler (dependant on boiler demand) and able to connect to hot water pipe work. A 3-5amp electrical spur(depends on boiler requirement)

I would look at an intergas boiler, getting great review with an innovative design for engineers to work on.

Also unsure if your boiler is condensing, as you will need to look at terminal position and able to run condense pipe work to a waste drain.

With deference to those in the trade, having had a combi boiler installed years ago it did exactly what you describe; freed up space by getting rid of the hot water immersion cylinder and the cold water storage tank.

Last year I organised a new boiler for my lad and the gas supply had to be upgraded from 15mm to 22mm - obligatory, and a pain to organise and install.

If your c/w tank is resting on sleeper-like beams there's the possibility the ends have been set into the wall brickwork. In old houses you have to be extremely careful removing them as the slightest knock sideways can knock the plaster off the wall of the adjoining room or passage.

The technique is to cut a section from the middle (with someone holding it) first, then without altering the angle from the horizontal gingerly pull each remaining portion from its cavity.

These days AFAIK all boilers are of the condensing type, supposedly more efficient......but a bit more costly and expensive to service or repair, being more complex.

I have just replaced our old back boiler in the living room with a condensing combi boiler in the kitchen.

I haven't kept detailed records, but doing the work myself except for connecting the new gas supply and commissioning the boiler, which I paid British Gas £117 to do, the cost came in at under £1000.
This included changing a couple of radiators which had not been replaced 3 or 4 years ago and fitting a filter system as most of the old pipework was retained after flushing out.

There is much more space in the former airing cupboard, and hopefully my gas bills will be significantly reduced. More space in the loft too without the old header tank for the CH and cold water tank.

It is great to have decent hot water pressure upstairs instead of 7 feet static head which was all the previous set up managed.

Now we have to decide on what is going to fill the hole in the living room wall.

Choose your brand carefully i had a potterton HE 24i or somthing like that (now common with many other names/brands i.e same parts for potterton and Bosch etc.) and i was replacing diaphrams expansion tank within a year and when we had good weather and switched it of for a while except hot water of course the flow sensor diaphram seized up!
Could be the water hardness or something but i seriously think you get what you pay for!
So choose your brand model carefully pay more now and pay less in the long term

Obviously it has to be commisioned by a gas safe certified person other than that if your are competent at soldering and bending pipes its straight forward if you understand the principles of plumbing in boilers. the push fit stuff is also fine and is pretty much all they put in new houses now!
My Father in law fitted my last 2 boilers and he used the plastic stuff back in 1997 and was fine for the 9 years i lived their and i used it at my last house due to ease, was fine for the 4 years i was at that house sadly he passed away in 2010 so im on my own now regarding boilers

I do all my own stuff but not gas and the biggest problem you may face would be to get a plumber/ gas safe engineer to come and put their name to work you have done especially if you do the gas too
So could be less hassle to get a decent gas engineer to do it for you as you could become stuck otherwise

If you have good water pressure locally a combi might be the answer. No HW cylinder or loft storage tanks so efficient on space. Only real drawback is that you have to wait a minute for hot water to arrive if it's a long run from the boiler, so if you just want to wash your hands you tend to give up just as the hot water gets there. In smaller houses it's not an issue. I'd go for Worcester Bosch or Vaillant - both are reliable. Not keen on Potterton or Glow Worm from experience. Any modern boiler, combi or otherwise, has to be condensing now - they are all really efficient compared with anything from 10 years ago. Ask for advice from a couple of local plumbers - they'll know what works.

Not entirely true and a misconception, a non- condensing boiler can be installed in certain circumstances e.g unsuitable flue termination, unable to suitably run condense drain and a few others but alternative locations within the household must be considered.

This is as part L energy efficiency regulations.

Many plumbers merchant will simply say you cannot fit them also

Vokera i believe are the only manufacturer to make a non-condensing combi.

As above, Worcester was the recommended and installed in my lad's flat.

Bear in mind if your shower is connected to the combi you might (if you have other people using the house) have issues with the water temp changing suddenly when someone else uses the hot tap. For that reason we've stuck with an electric shower even though the volume isn't so powerful.

Thanks all. Because of my time and availability, I'm going to get someone to do most of the job for me. Any thoughts on best installers? I don't hear great things (especially on price) about the energy suppliers doing the installation - true? There's no doubt it'll free up a lot of space. The current CH HW system is pretty new and of reasonable quality too so it's a shame to pull it out but it's in such a bad place - literally smack in the middle of a wall of a bedroom. Going to a combi boiler will also free up options to do a loft conversion.

Although I totally understand the reasons for the move to combi boilers and the need to free up space, I do lament (in the UK, anyway!) the death of the airing cupboard. Many modern houses or those that have been renovated now have virtually no storage space, because the cost is so high that it is considered almost a crime to "waste" what could be another bedroom/en-suite, etc, on something as frivolous as an airing cupboard. Although of course, a combi boiler won't be irresponsible enough to dry your towels!
There's nowhere to keep boxes or old curtains or any of the junk families create.
And it's very hard to get good servants, too.

Get a local Sas Safe registered plumber to install it. Don't go to British Gas or any national energy company - they just use subcontracted fitters working on a deadline who need to do the job as fast as possible and have no vested interest in after-sales support.
Fair point about the airing cupboard & servants though.

I have a small towel rail ready to plumb into the C/H system in the ex-airing cupboard to take care of that. I simply have not felt like pulling up the necessary floorboards yet.

Our house was built in 1926 so we do have a certain amount of space.

That's a good solution. I have to say, it's not something I anticipate needing here.

The house (still) has a large loft with built-in loft ladder. I've pulled out enough stuff to fill two 6 yard skips.

Is there any value in the kit coming out. The water tank is in good nick, there's a nice shower pump (they cost the earth), and all of various pumps and valves that are in great condition too.

So, have you left your amazing Inverness place, Richard?

There is scrap value in the copper pipes Richard, currently around £4 a kilo down here and any brass makes about £2 a kilo. there is also value in lead pipes if the house still has any.

Copper cylinders C £2.80 a kilo.

Other than that, I guess you might as well put stuff on ebay and see what it makes.

No, Jim. I bought this Cambridge place as a BTL place based upon my redundancy. It will help protect us from house price inflation in the South East. It's incredible that a (nearly) 3 bed semi in what used to be the less desirable part of Cambridge can be worth as much as my place on the Black Isle. There's no competition as far as I'm concerned! But the Cambridge house is near the Science Park, the Business Park, the guided bus way and the new railway station with direct connections to London. The Black Isle is only quiet and beautiful

Might prove useful with a lad at uni...!

Could you not relocate the tanks to the loft? Save having to buy a new boiler ...

Richard, if you're down that way of a weekday, drop in the office? St John's Innovation centre...

Ah cool - I will do that - I'm sure to be back soon. My body feels broken right now though. Jeez Stansted is horrible these days - you really feel like cattle going for slaughter! Think I'll try CityJet straight into Cambridge next time.

I'll PM my phone number and email, Richard.

I have had no hot water or heating for 4 days now, apparently the pcb board has failed on my boiler just waiting for it to be repaired. Its a 2 mile walk in the morning to have a showeR at the gym - thank god I kept my gym membership going.

Getting it done next week - thanks for all the advice.

Making good progress on the house in general - it's not quite "Changing Rooms" or "DIY Rescue" but it's amazing what you can achieve in a short space of time when you put your back into it.

Here's a pic of the offending kit - just where you'd put a double bed

Pic not working for me MRS ?

Should be now - fighting the App

You've got a Potterton then I presume?

Spot on,