independent zones in existing dwelling >150m2?

Hi there,
Can anyone tell me what the building regs say about replacing a boiler in an existing house over 150m2?
I have two quotes from corgi registered plumbers. One says I have to establish two zones that can be independently controlled in terms of temperature and time (involving two sets of new controls, zone valves and much work on the pipe layout, as well as TRVs), the other is equally adamant that this is for new-build and that TRVs on all the radiators is enough.

Both recommend upgrading from a gravity-fed to a closed system... Fine. TRVs on most of the radiators... Also fine. But a couple of thousand quid in work to zone everything seems way over the top.

I cant find a definitive answer online. As an amateur, the building regs seem intentionally complicated/ambiguous. Even a call to the building inspector was met with "I've no idea".

Any help/advice would be much appreciated!

All the info is here http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_DOMHEAT.pdf page 10 - 16

and http://www.est.org.uk/uploads/documents/housingbuildings/CE51 Final.pdf

and my understanding is you have to have the additional zone although it could be an installation nightmare.

You have not described your layout.

However zoning is usually per floor of the property and most properties are supplied floor by floor.

Zone controls are not that complicated, to buy the bits is less than £100 and to fit we would charge about £150 as part of a large job. Double that for two zones and thats £500 but not £2000.

He sounds a bit pricy!

Tony

I'm afraid I dont know the layout. The house is about 12 years old, with 10mm microbore feeds to the radiators. In an ideal world I guess there would be separate 22mm spurs (?) to feed top and bottom floors but both plumbers who visited suggested there would be considerable work in raising floorboards to trace the pipework and possible replumb parts of the system. The 2k was an average of two guesstimates on their parts, so I wouldn't like to cast aspersions as to VFM at this point.

Anyway my reading of the info I was kindly pointed to by Gasguru suggests that the only ambiguity is in the amount of work done, "...except where the boiler only is replaced, in which case reasonable provision for a space heating system would be to control as one zone".

Possibly the conversion from a gravity-fed system will invalidate this and may be more trouble than it's worth...?

Cheers All.

Agile said:

You have not described your layout.

However zoning is usually per floor of the property and most properties are supplied floor by floor.

Zone controls are not that complicated, to buy the bits is less than £100 and to fit we would charge about £150 as part of a large job. Double that for two zones and thats £500 but not £2000.

He sounds a bit pricy!

Tony

Click to expand...

I have to say that if you have a traditional microbore then both quoters were taking the Mickey ( or just a bit thick! ).

Microbore is traditionally fed from a single manifold on each floor fed hopefully at 22 mm bore but possibly at 15 mm.

In that case finding the manifold and the single feed is very easy. I would go further to say that a good quality installation would have each manifold kept accessible !

Tony

Agile said:

I have to say that if you have a traditional microbore then both quoters were taking the Mickey ( or just a bit thick! ).

Click to expand...

You don't actually have to say that - you could just concentrate on the technical aspects without judging a plumber you've never met or corresponded with.