Problem Rads - New Boiler Required?

boxtysugarbulb

Hello All

We have a 3-bedroom semi-detached bungalow, built about 50 years ago. The oil-fired boiler is from 1986, sitting in a boiler-house at the back of the kitchen. It takes gas-oil. There's 9 rads - 2 of them doubles. A small rad in the kitchen, closest to the boiler, is at least 20 years old. It works fine and gets very hot, although it's not big enough to really heat the kitchen. (I use a gas-fire in the kitchen if it's cold, so no bother!) The kitchen rad doesn't have a TRV, but all the rest do. Of the other 8 rads, 6 were new about 5 years ago, and the other 2 (in the living room) are about 10 years old. After the kitchen rad, a branch of the pipework heads into 2 bedrooms with a single and double rad respectively. Everything's fine there. The 'mainline' pipework heads into the dining room (1 rad - fine) and then (I think) into the living room, where the first of the 2 rads is fine, but the one further away gets fairly warm, but never as hot. It also takes a fair while to even get warm. (Also, the pipework underneath the floor in this area sometimes seems to 'groan' a bit when the heating's on, making a noise every 20 seconds or so. I think this might be more when the heating is going off though.) Although they're under the floor, I'm guessing that the pipes next run out into the hall. There's a rad in the hall and the hot press with the cylinder is there as well. That rad's fine, as is the hot water. I don't know which is first in line of the pipework. Finally there's a rad in the bathroom - which warms up, but doesn't get hot - and another double in the third bedroom - which gets lukewarm at best. There's only a simple 24-hour timer for the boiler, with no separate 'water only' option. There's no immersion on the hot water cylinder. The boiler gets serviced yearly and the engineer - who is not a plumber himself - has told me that the boiler itself is still working fine, but the burner needs replacing - (although he still manages to keep it running with some TLC!). Finally, the cold water cistern in the loft is trickling away into the overflow pipe. The problem rads don't need bleeding.

Now it may or may not seem obvious from the above ramble, but I admit to not having much of a clue about plumbing/heating systems. Please take that into account in any replies!

Anyway, I've got the number of a plumber to ring to fix the overflow on the cistern. I'm guessing that it's just the ballcock needs replacing, but are there any other reasons why this might happen? Could this be affecting the 3 rads not heating up in any way?

While he's here, I'll ask the plumber about the problem rads. I've read in other threads about 'balancing' the rads/cylinder. Would this be the first thing you would try if you were the plumber? How long should it take? What other causes could there be? Is it possible that the 1986 boiler just doesn't have enough power for all the rads? The label on the side says it has an output of 23kw. Does that sound enough - or would the output have degraded after all these years? Is there a way to tell? Could the circulating pump (that I've heard mention of) be the problem? It's probably 1986 as well.

I seem to recall the plumber who replaced the rads 5 years ago saying that they were on 2 'runs'. Does that mean anything?

The pipe in the bathroom is silver in colour. I've read about 'gun barrel(?)' pipes; does this sound like one? If so, could it be a problem? The bathroom and third-bedroom rads are connected to it.

I read that one rad should _not_ have a TRV valve. That's the case with our kitchen rad. I don't understand the logic, but does it matter which rad is without the TRV?

Should both rads in the living room have TRV's? Should both rads get equally as hot as each other, or could the rad that isn't getting as hot be doing so because its TRV considers that the temperature in the room is sufficiently hot already - i.e. is there any interaction between the 2 TRV's.

I was thinking of asking the plumber to do a quick survey of everything and provide a sketch of what pipes go where? Is this something plumbers often do? Would an experienced plumber be able to tell what pipes were going where, without having to 'uncover' the pipes below floors etc?

If I do need a new boiler, I'd be interested to know what make/size people would recommend, given the details above. I understand that all new boilers/burners use kerosene rather than gas oil; is the best way to change simply to drain the tank and refill? I also understand that the new boilers are all condensing, and have the 'balanced' (horizontal?) flue which gives out the plume of exhaust fumes? This would probably be just beside the kitchen window, which doesn't sound appealing. Do the fumes smell; are they dangerous/hot; could they damage the window? I've also heard of problems with the condensate pipe tending to freeze in cold weather; is this common?

If I do get a new boiler, would it be an easy thing to have separate hot water and heating - ('zoning' I believe it's called?) - or does that involve new pipework? If so, would it be just as easy to get a new cylinder with an immersion?

Any thoughts on the above would be much appreciated. Thanks in advance!

heinbloed

Concentrate on the question please:)

If I do get a new boiler, would it be an easy thing to have separate hot water and heating - ('zoning' I believe it's called?) - or does that involve new pipework? If so, would it be just as easy to get a new cylinder with an immersion?

These boilers are combi boilers. They are efficient if chosen correctly, modulating within in the demanded output. Not more and not less.

You need no 'cylinder' for these, no thermal storage tank, copper barrel.

Get a heating engineer in who will plan your heating system.
Get a demand calculation done (EN12831).

aujopimur

It sounds like you have poor circulation,I'd try balancing the system first and maybe a new pump would be worth a try.
With regard to zoning, it would depend on the layout of the existing pipework.
I,ll stop for now as my keyboard skills are limited, just a one finger jobby.

boxtysugarbulb

heinbloed wrote: »

Concentrate on the question please:)

Not as easy as it looks sometimes!

heinbloed wrote:

These boilers are combi boilers. They are efficient if chosen correctly, modulating within in the demanded output. Not more and not less.

You need no 'cylinder' for these, no thermal storage tank, copper barrel.

Get a heating engineer in who will plan your heating system.
Get a demand calculation done (EN12831).

Nope, I'm not after a combi. Sorry, probably my fault for not explaining well enough. I had considered a combi, but they seem like more trouble then they're worth for my situation. (I don't think there's any boiler-house oil models anyway from what I could see.) I was more thinking of a heating control which allows you to either have heat&water or water only, so that in the summer I can just have the water only. I can live with things the way they are simply by turning down/off the rads in the summer, but if it was easy to do that at the control, that would be handier. A cylinder with an immersion was another option. It all comes down to cost and convenience I guess. Am I making more sense yet?

boxtysugarbulb

aujopimur wrote: »

It sounds like you have poor circulation,I'd try balancing the system first and maybe a new pump would be worth a try.
With regard to zoning, it would depend on the layout of the existing pipework.
I,ll stop for now as my keyboard skills are limited, just a one finger jobby.

Thanks for the reply. Much appreciated. I'm hoping that balancing will indeed fix things.

heinbloed

Well, you do now.

TRVs ( thermostatic radiator valves) can be fitted to all radiators. These will close the circulation of hot water through the radiators. Forget about upstairs-downstairs zoning, such primitive plumbing methods lead to high bills and low performance.

If you have to use oil for your primary energy source go for a modulating oil boiler.
Most plumbers active here in the forum haven't seen these so can't comment on them.
Get a heating engineer in who will design your CH+DHW system. There might be things overseen until now which aren't obvious to the virtual amateurs.
For DHW in summer time the combustion of organic matter is the least efficient method to provide a household with DHW.
Again: contact a heating engineer.

boxtysugarbulb

Thanks for your viewpoint heinbloed. I'll stick with simplicity over efficiency for now though I think.

I guess just turning off/down the rads in summer is the easiest option, as opposed to zoning or an immersion. If anyone has a different opinion, I'd be interested in hearing it.

whizbang

Finally, the cold water cistern in the loft is trickling away into the overflow pipe.

is this where your heating water is going?
pressure gauge fitted ?

Also check the TRVs on all rads. many cheap units, often not fitted properly, but remove the plastics anyway and check the actuating pins for free movement

gdavis

my advice would be,disregard everything heinbloed says as he is full off sh1te.dont know what his agenda iswith his ill informed replies and his bizarre ramblings,for proof of this,feel free to look through his previous posts

shane0007

gdavis wrote: »

my advice would be,disregard everything heinbloed says as he is full off sh1te.dont know what his agenda iswith his ill informed replies and his bizarre ramblings,for proof of this,feel free to look through his previous posts

Oh God, +1 +1 +1..... and then some more +1's

You have to admit though, his posts are very entertaining and I have had many an evening quietly chuckling to myself here at the computer.

Billy Bunting

gdavis wrote: »

disregard everything heinbloed says as he is full off sh1te.

I honestly believe that the Mods should insist this statement should be used by Heinbloke as a signiture, a clear warning to new member.

GASMANN

gdavis wrote: »

my advice would be,disregard everything heinbloed says as he is full off sh1te.dont know what his agenda iswith his ill informed replies and his bizarre ramblings,for proof of this,feel free to look through his previous posts

jaysus gdavis calm down, and then call a heating engineer....

JohnnieK

:D:D:D:D:pac::pac::pac::pac::pac::pac: hahahahahahahahahahahahaha.