UF heating controls

[Dazz0i]

New build i'm wiring, the plumber doesn't seem to have much knowledge on what he's installing in regards as to wiring required.

I've not really come into much UF heating installations, and any before the guy we used to use was really clued up on what he required to do his work. Or he used RF controllers.

Anyhow, today he mentioned a secondary pump at the manifold for the heating which would require power. Then spoke of control motors.

The manifold is in the kitchen, so getting a power from a fused spur to the pump isn't a problem. The cable for the motors he mentioned 5 core, but 5 core is flex, surely that can't be used as fixed wiring?

I'm awaiting info back from the plumber on what he requires, but i like to be armed with a little knowledge before hand.

Any light that anyone could shed on this situation would be most appreciated.

 

[Christhescott]

think the last one I did needed 5 cores between each manifold. and then a twin from the maniold to the valves/boiler. so a twin and a 3 core. room stats are wired in 3core, one stat for each UFH zone. Will need a clock and not a clock stat also. If there are radiators upstairs then you will need another clock for them and the Hotwater.

By motors does he mean thermostatic heads? They are just 2core and they are prewired.

The plumber should have wiring diagrams for the kits to be honest.

 

[electronicsuk]

Nothing wrong with flex for fixed wiring, although I believe it must be at least 0.75mmsq. Sorry, can't remember the regulation number or be bothered to dig it out right now. Hopefully someone else will be helpful enough to check up on it.

 

[Taylortwocities]

Nothing wrong with flex for fixed wiring, although I believe it must be at least 0.75mmsq. Sorry, can't remember the regulation number or be bothered to dig it out right now. Hopefully someone else will be helpful enough to check up on it.

The fuse will be there to protect the wiring and (probably) the control stuff.
Most UFH systems specify a 3amp fuse and the cable size must not be smaller than can carry 3 amp.

So .75mm² or 1mm² condustors should be fine.

Many UFH systems come with their own wiring centre to which you connect the pump, valves, manifolds, zone thermostats and call to the boiler.
How many conductors you need will depend on the layout and where things are located.

VERY IMPORTANT
There should be one switch will turn the power off to ALL of the heating systems, boiler, pumps, etc. I have seen lash ups where there is a power feed for the boiler and a separate one for other heating controls.
This is dangerous and must not happen as it provides the possibility for power to appear on circuits that should be powered off.

 

[electronicsuk]

Nothing wrong with flex for fixed wiring, although I believe it must be at least 0.75mmsq. Sorry, can't remember the regulation number or be bothered to dig it out right now. Hopefully someone else will be helpful enough to check up on it.

The fuse will be there to protect the wiring and (probably) the control stuff.
Most UFH systems specify a 3amp fuse and the cable size must not be smaller than can carry 3 amp.

So .75mm² or 1mm² condustors should be fine.

The comment you picked up on wasn't with regard to fuse sizing, but more a regulation from BS7671 that I recall stipulating the minimum size of conductor to be used in fixed wiring. I may, of course, have completely imagined it.

 

[Christhescott]

Nothing wrong with flex for fixed wiring, although I believe it must be at least 0.75mmsq. Sorry, can't remember the regulation number or be bothered to dig it out right now. Hopefully someone else will be helpful enough to check up on it.

The fuse will be there to protect the wiring and (probably) the control stuff.
Most UFH systems specify a 3amp fuse and the cable size must not be smaller than can carry 3 amp.

So .75mm² or 1mm² condustors should be fine.

Many UFH systems come with their own wiring centre to which you connect the pump, valves, manifolds, zone thermostats and call to the boiler.
How many conductors you need will depend on the layout and where things are located.

VERY IMPORTANT
There should be one switch will turn the power off to ALL of the heating systems, boiler, pumps, etc. I have seen lash ups where there is a power feed for the boiler and a separate one for other heating controls.
This is dangerous and must not happen as it provides the possibility for power to appear on circuits that should be powered off.

I was struggling with how best to isolate the entire system safely. In the end I fed the the entire system boiler, pump, timeclocks and UFH manifolds, wiring centres etc from a sw/fuse neon next to the boiler which was marked 'heating.' But as the UFH were in different parts of the building should they not have had a localised means of Isolation?

 

[Dazz0i]

Fantastic guys, gives a little more on what is to be expected.

I've just spoke my boss from what i gather, it's going to be the "usual guy" to do the UF heating. The plumber that was there today is only doing the hot 'n' colds, boiler and cylinder. l think it's cause to do with that the other bloke can get the stuff SOOO cheap it's not worth us going else where for. So hopefully a little more info will be provided.

There's gonna be a boiler clock in the cupboard with the boiler and then and RF room 'stat for the radiators upstairs. Then another 'stat for the UFH downstairs