Heating hell this winter!

[nottingham_ed]

Hello all
I have siged up for this forum as I need some sound advice. I have had about 5 heating engineers to the house now - they all have different views and all charge very different prices.

I moved into a new home in June last year - it is a 100 yr old Edwardian semi - 2700 sq ft, 5 beds, 2 baths. It is single glazing and is fairly draughty. The ceilings are high, but not very high - about 2.7mtrs.

Fot heating, the previous owners had a combi fitted 8 years ago - a WB Greenstar HE plus 35. This gives central heating output of 35Kw modulating from 11 to 35.5.

The problem is this - the rads just don't seem to get hot enough. We have had a load of new rads put in as there were a lot of older ones. This has helped but not a lot. The tops of the rads are generally quite hot, but the bottoms are generally mildy warm. I don't think this will be a sludge problem as they are new, and some of the rads do heat all the way through, but most don't.

The other problem is that when we have a shower, all the rads go luke warm for about 20 minutes.

People keep saying that we should be on a system boiler set up with a cylinder - thing is there are only 2 of us living here so we don't need masses and masses of hot water. In fact, one of us works away 12 days a month so a cylinder full of hot water would be a waste.

I go to other people's houses and the 1st thing I do is feel their rads to see how hot they are - and mostly they feel a lot hotter than ours.

Can anybody recommend what kind of system to go for - bear in mind that there are no WB boilers that give out 35kw central heating.

If we do revert to an unvented system, is that going to cost a lot more to run?

Thanks for any advice you may have.

 

[ecowarm]

Sounds like a build up of sludge in the system, a good power flush will sort it.

A combi is not ideal in a large property because it gives priority to the hot water, but if you can live with it if the heating is working properly.

 

[Gray0689]

If there only 2 in house why do you need a house at 2700sft buy a smaller more efficient house
That's the best advice I can give as your house sounds very inefficient single glazing combi in that size of a house I would not put that in

 

[villa_tom]

If rads are cold at bottom then a flush will normally do the trick even if you just take the worst rads off and manually flush them. Also try a magnaclean or something like that to stop more sludge entering the system once flushed and cleaned.

 

[Centralheatking]

AS a quick solution I would because there are only 2 of you zone the house and only fully heat the bits you use and keep the ones you dont at a much lower temp but with frost/low temp protection.

While its drained down to put in the zone valves flush it out.

centralheatking

 

[Blackcatgas]

Turn off all the rads that get hot evenly, do the rads that dont get hot evenly then get hot?, if they do then the size of the pipes are probably too small, ie 5 big rads off 15mm pipe,If they still dont get hot they are probably full of sludge .or the pump could be worn out. Youve had 5 plumbers round, theyve all probably tried to balance all the rads to no effect, a 35kw boiler will heat a very very large house btw, 6 bedroom manor house big.
The rads will go cold when you run the hot water, the boiler prioritises the hot water over the heating.

 

[Blackcatgas]

AS a quick solution I would because there are only 2 of you zone the house and only fully heat the bits you use and keep the ones you dont at a much lower temp but with frost/low temp protection.

While its drained down to put in the zone valves flush it out.

centralheatking

He could do this (although not as effectively) by turning down the trvs (if theyre fitted!!!).

 

[oldplumber]

remember a combi only needs the 35kw to heat the water, it modulates right down to 18 or so to warm the house. As said sludge is the issue or a badly designed system, Ive had combis in 5 bed houses and run one now in a large 4 bed victorian 3 storey apartment ! windows provide ventilation when closed and Im happy to be ungreen as I prefer to breathe fresh air, not the dogs farts, and the combis fine for me and the family and the heatings good enough to keep the place warm even if the missus is running one of her small baths! My choice for a combi and they are great as long as you accept minor issues with water flow from multiple taps. get in someone who knows there stuff to sort you out, you dont need a new boiler and unvented cyl that some will try to sell you.

 

[tamz]

Big house, big bills i'm afraid. No matter how you choose to heat it, it will not be cheap.
When the previous owners had the boiler installed was it a boiler swap or a full system? If it was a swap the existing system may be a one pipe system.
If you have trvs on the rads with a 1 pipe, unless they are low resistance valves, they can kill the thermosyphonic (gravity) circulation through the rads.
If the system is a 2 pipe, it may have been badly installed with wrong sized pipes or added to over the years and the pipes are now too small for what they are feeding. With a house this size they should be minimum 28mm leaving the boiler and reducing to 22mm and 15mm to suit the load.
None of your cures will be particularly cheap. I suspect the system needs part repiped with bigger pipes but the only people who can truly answer is the ones who actually see what you have. Get a decent plumber/heating engineer in who has been around for a while. Ask neighbours or other locals for recommendations and speak to them.

 

[markproperjob]

And get your EXPERIENCED and preferrably LOCAL plumber to quote to fully powerflush the system before/as any alteration work is carried out.
in a lovely old building with a maze of pipework hidden away, there are many points that sludge can restrict the flow to rads, and cool spots/cool bottoms to rads usually indicate a build up of iron oxide.
the hot water running will make rads cool off, if priority hot water design.