High fuel bills too. If the radiators aren’t circulating then the heat exchanger in the boiler will overheat and a temperature sensor shut the burner down prematurely (or reduce it to the lower of two burner settings) – you’ll have low fuel bills. It sounds to me as if the house in general and particularly the extension is poorly insulated.

Do ou have 25Omm in the roof, 100mm in/on the walls and 100mm under the floor?

Have you done as advised by a few above?#

Go around and turn off all the thermostatic valves, run the heating, bleed the rads in the extension, and see if you can get them evenly hot. If you can achieve this, you are halfway there. It will take you half an hour and cost nothing 🙂

You could always speak to these guys, http://www.sapservice.co.uk/. Speak to John and see how they could help in determining heat loss and/or heating performance. I doubt if they’ll be able to give specific boiler/micro-bore advice, but they will be able to help on the strengths/weaknesses of the overall house. Just tell them Simon the roller shutter guy sent you. 🙂

The hardness fo the water should have very little bearing on the effectiveness of a closed heating system. Unless it has been leaking and water has been continually running into the system.

Once the system is full, the same water is circulated around the system until some is either lost through small weeps or some work carried out. Therefore the amount of scale should only be the amount of scale contained in the volume of water contained in the system in the first place. This will not be a great amount. Sludge or ferrous oxide could however form for a variety of reasons, usually poor system design and or maintenance.

Although from my experience and I’m going to generalise now, but I’m allowed!, the most common problem is oversized boilers and undersized pipework.

Can I repeat again.
The most likely problem is a circulation issue.

As you can already get some heat to the rad do as mentioned above and see if the whole rad heats up. Getting some heat to the rad suggests return being an issue, pipe size/blockage/pump size (but not necessarily) but until you know if it can get there and come back your a bit stuck for what to look for or do next.

If you don’t understand the instructions say so and I or another will try and explain it another way.

Any normal domestic pump that’s working correctly should be able to get heat to a rad through microbore that is clear when everything else is off. Assuming distance isn’t that of a Mansion/Castle.

You’ve fallen for the biggest mistake going.

If heat is getting to it then the blockage must be in the return is total and utter rubbish.

CG whilst your plumber may be good and pretty diligent you may need someone with a bit more knowledge of heating systems and their design.
However I don’t envy you trying to find someone as plumbers are a fickle bunch and someone always proclaims to know best or the magic cure! From the sound of things you may have a few problems which are contributing to the overall problem.

To save me re-reading is your boiler a combination boiler or have you got a hot water cylinder?

Out of interest how did your plumber balance your heating system? He should have used a thermometer to stand any chance of succeeding.

If heat is getting to it then the blockage must be in the return is total and utter rubbish

Nope never said that.
I said “suggests” and then a list of other possibles.
A blockage could be in the flow or a valve or the rad or the return or not a blockage at all.

Eliminate the obvious then move onto the harder options.

Or to save a load of hassle after checking it’s not the pump that’s just knackered just repipe the extension now and have done with it.

Note this is all suggestions without having any knowledge of the layout or installation or the area or the windspeed where you live. You may die if any advice given is used.

Suppose that the above worthy types do come up with a solution, what kind of underwear will you be wandering around in?

My point is it doesn’t even suggest a problem with the return. It could be anywhere in that circuit, just because the radiator gets hot people always seem to think it is the return. I have lost count of the number of customers / builders / even fellow plumbers who think this and cannot grasp the fact.

So I’ll substitute must with suggest – it is still total rubbish.

You could prove which pipe it was relatively easily, but I guess all the experts here know that.

And sorry not a personal attack on anyone but more an attack on those that work in the industry that give it a bad name through ignorance.

If heat is getting to it then the blockage must be in the return.

If there is a blockage the whole leg will be cold you’ll have no flow in any of a blocked leg whether the block is in the flow or return.

Or to save a load of hassle after checking it’s not the pump that’s just knackered just repipe the extension now and have done with it.

😮

So I’ll substitute must with suggest – it is still total rubbish.

And my point being that it could have been any of the issues I posted and not just a possible pipework blockage. The “return” could just as easily be referring to the fact the pump can’t overcome the resistance to get it back on the return rather than a blockage. Your right in a blockage could be on the flow.

Are you going to try and help? You say you have relatively simple solutions to ascertain which pipe may be blocked or not but haven’t tabled them. Are your suggestions simple enough for the householder to carry out or do they involve disconnecting radiators etc?

If there is a blockage the whole leg will be cold you’ll have no flow in any of a blocked leg whether the block is in the flow or return.

For “Blockage” read “partial blockage” as heat is clearly getting through.

Guys – please!

I’m waiting on a call from a plumber who works with Alpha boilers. However, I have noticed that it is not firing up as noisily as usual and there has been a change in its normal sounds. Also the condensation seems to be really huge bursts of steam.

Again, next to no heat from kitchen rad, utility one dead and small amount from shower room. Two lounge rads have differing amounts of heat.

Thanks again for all the suggestions. 8)

Right apologies to all as we will get as bad as all the bigoted people about rugby!

Anyway it sounds like a walk in the park compared to my current plumbing challenge…..

You know exactly what the test is as it does involve removing radiators……

CG – not sure that the boiler is the issue. Have you got a hot water cylinder?
I ask because one of my first NHBC fault finding jobs involved a heating system with microbore, and radiators not warming. 3 plumbers had tried to cure the problem which turned out to be a simple control issue.

And I feel I should rise to the challenge of helping now but don’t think you are local to me here in Kent. Although am probably in Chippenham at the end of the month.

If it were me I’d put up with it till summer then rip the bloody lot out & re-pipe with 22mm – 15mm. You could waste twice the cost of re-piping messing about with this & that. Get your plumber to give you a quote for re-piping the lot. If the rads are decent he can re-use them, likewise the boiler.
No amount of power flushing will get rid of 20yrs of sludge sitting below the inlets on a rad. Them rads need to come out & have a good flush upside down with a hose running through them. While your at it stick a new pump in.
My old house had the same problem. Lashed on microbore here & there. I spent a few weeks replacing all of it over the summer & come winter it was like a different house. And this was an old place, double brick skin so no cavity wall etc. It was warm as toast. Cost more to heat but thats running an older “character” property for you. 🙂
Some good advice been posted on here, but its just a house so civil engineering type technical studies on pipe runs are a bit ott. Stick to the old rule of thumb, 22mm with 15mm branches. And no branching off branches, put a drop in for each rad & do it properly. My kitchen for example, that had 4 windows & a door. One rad in there kept it warm, same with the dining room. Had an open staircase, so took out the old rad at the bottom of the stairs & put a big double finned Barlo roundtop in away from the stairs. Christ did that thing give out some heat. Switch off the heating & the place would go cold quickly but it was an old house. Short of cladding the place in insulated render theres not much you can do.

If it were me I’d put up with it till summer then rip the bloody lot out & re-pipe with 22mm – 15mm get some decent insulation in before wasting money on a new heating system.

😉

Forget all I said earlier – them are the generalizations that annoy me…..

22mm is fine etc

Grrrrrrr