Back boiler?

[T i m]

H All,

I just popped round my brother in laws (general builder for 35 years) and he was talking about the back boiler he has had in his house for the last 25 years needed 'fixing'.

He said he had mentioned this to a Corgi / heating eng and it was suggested that back boilers aren't 'allowed' any more (ie, little / no chance of buying a new replacement)?

My BIL questioned that if this was the case and he has to rip his house up to fit a 'modern' boiler elsewhere, who was going to compensate him for all these changes (devils advocate question)?

Any thoughts or current rule confirmation please?

All the best ..

T i m

[Geo]

No idea - but they are still for sale:-

Geo

[Andy Hall]

Yes, the assessment points system on the ODPM web site covers it.

a replacement is required, then the points can be applied.

I just did this exercise for my parents who have a back boiler in the living room in a position in the centre of the house.

Using the tables for their example:

House type and fuel (detached, NG): 590 points

Boiler in new room? (yes, they can't require you to install a condensing boiler in the main living room) : 350 points

Extended flue > 2m (no): 0 points (would have been 200)

Condensate pump or soakaway needed? (yes): 100 points

Total is 1040 points. Above 1000 points it is not required to install a condensing boiler and so they could choose to replace the existing one. The fitter fills in the declaration, and that's it.

However, if the criteria aren't met, then a condensing boiler must be fitted and no your BIL can't be compensated for it other than in lower fuel bills.

[T i m]

Brilliant, thanks for that Andy.

So in this case 'Points mean' the possibility you can replace like with like ;-)

Would you think a new back boiler would be *much* more efficient than a 25 year old one (allowing for wear / tear etc) and how far off that would it be compared to a new 'super duper' one do you think please?

All the best ..

T i m

[T i m]

Thanks for that .. so as long as you meet the 'points system' (as mentioned by Andy) you can still get / fit them it seems .. ?

All the best ..

T i m

[Andy Hall]

Points mean prizes.

Yes you can.

The SEDBUK database doesn't have figures for models that old but pre-1990 Baxi back boilers had an efficiency of 65% at best. Later models manage up to 79%. Condensing boilers manage in the 90-91% range.

So... if your BIL can go from a 65% to a 90% then it is worth having. Depending on what is bought, there's not a huge difference in purchase cost of the boiler - although there is the re-siting issue.

I don't particularly like being manipulated into product choice by the government, but I don't feel that that aside, this is necessarily that big a deal so is worth looking at even-handedly.

[T i m]

Depending on what you may have to do to put in a new boiler I suppose (if that's what you meant?).

His kitchen (open plan into the lounge with the back boiler) has just windows on the only external wall. Any relocation will involve fairly extensive uprooting of (fitted) carpets, floorboards, water / gas pipes, electric spurs not to mention finding a suitable external wall and thats probably on the opposite side of the house (to the existing back boiler) and therefore end up in the very full (builders) garage?

(Ignoring the emmisions for a while) I think it might take many more years than he has got left (probably in that house anyway) to recoup the cost of the relocation work over the extra fuel costs?

All the best ..

T i m

[Dave Plowman (News)]

The problem with a back boiler is that it pulls in hot air from the room and shoots it up the chimney - to be replaced with cold from outside. Which was known to be inefficient long before condensing boilers arrived. Hence balanced flue boilers which have been around for many a year.

Personally, I'd investigate replacing it with a modern condensing type. The fuel savings may well repay the cost quickly. And, of course, there are the safety benefits of a room sealed device.

[Andy Hall]

Not really. You can see that they don't factor ancillary works into the equation.

How about the loft? This may avoid some of the pain of the water pipe re-routing in that typically they can be run upwards from the airing cupboard. Presumably the cylinder is currently gravity heated. It would need to be converted to fully pumped but that's not too bad. The main issue would be provisioning a gas supply to the loft.

In any event flues are not too bad. If long lengths are needed, there are boilers which will happily use 50mm high temperature plastic waste pipe for runs that can be up to 20m or more.

Unfortunately the government has only taken a limited range of issues into account. Decorations are not among them....

[T i m]

Well that's a thought, though being a semi there isn't a flat external wall to hand (unlike my 'semi terraced) ;-)

This may avoid some of the pain of the water

Good point ..

Presumably the cylinder is currently gravity

Pass, could be ..

It would need to be converted to fully pumped but that's not

Not for him especially ;-)

The main issue would be provisioning a gas supply to the

Again, as you say, could probably brought up from below .. maybe via the (to be) unused chimney (assuming he also does away with the fire front that is)? And as he recently went round after the CORGI man fixing the gas leaks from the unfinished joints ..... ;-(

And I assume could also be vented through the roof tiles via a suitable tile and terminal?

So it would seem ;-(

All the best Andy ..

T i m

[T i m]

Hmm, good point .. didn't some boilers require an input duct so they do actually collect their input air from outside (like a balanced flue jobby) though? I admit the front fire would still consume room air and send heat into space ... but wouldn't the exhaust gasses (back boiler and front fire) give some of their heat to the chimney breast / internal stack and hence to the house on their way out (where a balanced flue wouldn't)?

Worth investigation indeed (but reluctantly no doubt). ;-)

All the best Dave ..

T i m

[Andy Hall]

I'm not sure that the pipe could be run inside the chimney, but perhaps it could follow the route of the pipes to the cylinder and thence to the loft?

Yes, or even a suitable ridge tile.

[Dave Plowman (News)]

Not seen that arrangement with a back boiler - although I suppose it's possible.

Yes - some 'flue heat' won't be wasted. But the majority will. ;-)

[Andy Hall]

Certainly ventilation is needed for a back boiler.

For a fire only, it depends on the type and rating of fire.

It's true that a back boiler flue will give some heat back to the building, although since there is a flue liner normally used, I'm not sure that it will be a lot.

For a balanced flue, it would really depend. If the flue is short, then heat will tend to be expelled. If it's a long concentric flue, the exhaust is usually (always?) in the centre and some heat will be transferred to the intake air.

Having said that, condensing boilers are so efficient anyway and release comparatively little heat via the flue, it should be a non-issue.

[T i m]

Why not Andy? I mean if the chimney is not to be used again then doesn't it just become a 'riser' ?

Ah yes .. and one of his 'pet hate' areas.

By that I mean in inapproriate (?) use of over-large ridge tiles when houses are being re-roofed?

I was actually looking at that on my Mums house the other day compared with those of next door (both sides). Her's were a nice low profile ridges and shoulders / hips (or whatever the bits at the end of a semi roof would be called) .. the ridge tiles may have been tall but the others were lower so all looked in 'scale' (whereas next door looked more like a large clay pipe filled with cement and the sides and top were 'bodged' at the join to make them fit) ;-(

Would there have been a reason for this (ie, you can't get the low profiles any more) or another common example of the 'can't be bothered, they will never notice, no pride' attitude demonstrated by many of the trades today?

Ho hum ..

All the best ..

T i m

[Andy Hall]

How would one get the pipe in there? It can't be plastic, remenber...

Can't say I've thought about it. A few years ago when our Aga was installed, we elected to have a conventional flue model because it was the most convenient for the installation position. The flue runs directly to the loft, then at an angle following the roof slope and finally to a ridge tile terminal. The profile follows the existing tiles and it isn't noticable from the ground.

[T i m]

Hmm, I was imagining an access hole made in the face of the chimney in the loft? The pipe(s) could be fed down from the chimney top before the pot is shillded (rain cover / vent) ?

Well, the next time you are looking at a roof (from the ground), check out the profile of all the ridge tiles and see if all the houses in the row look the same? ;-)

A few years ago when our Aga was

That's good and my suggestion is that not all roofers / builders 'would bother' / 'are able to source' the correct ridge / hip profile?

All the best ..

T i m

[Andy Hall]

Obviously one could make the hole, but I'm not sure that even then one could get a long length of copper tube down the chimney, even at an angle. THen there is the matter of supporting the pipe.

In the context of rows of houses, I see what you mean, especially if there is a re-roof job.

Oh of course. I had to find out who the manufacturer was and then find a local specialist supplier. I then painted the tile of the new terminal with some milk and general crud a couple of weeks before fitting to encourage growth of suitable flora and fauna to match existing. Two months after fitting, the colours had blended with the

15 year old existing.

[Owain]

Then you would have to say "oi, roofer, no" and give him a slappin, innit.

Owain

[Ian_m]

My mate had his backbolier replaced couple of months ago. Fitter did a totting up exercise of fitting a modern boiler, which would not be easy due to existin location of back boiler in center or terraced house and fitted a replacement (Baxi ?) back boiler. Also converted to fully pumped HW as whilst at it.. About £2.5K I seem to remember, inc hearth and coal effect gas fire front.