re-wiring - heating or not... as standard

[matt.leung]

when doing a re-wire, or estimating, do u account for the central heating wiring, or is that an added extra....?

 

[ProDave]

It all depends if it needs it.

If the main wiring is old, but the central heating was only installed say 10 years ago, that wiring may be perfectly okay. But the only way to be sure is to check it out.

But on the scale of things, the CH wiring is a very small part of a complete rewire, so one could argue you might as well rewire it as well and it wouldn't add much to the overall cost.

 

[green-hornet]

I agree with prodave, the best way to do this is to include everything, and let the customer decide. I always ask at quote stage, many times the plumbers have been on site at the same time and they will give me the spec, most now use the remote senders so only wiring is at the boiler. If its a multi zone you will have to price for various wiring plans like Y plan for instance, plus pumps, valves and all that kind of stuff that goes over my head.

 

[kme]

Herein lies the issue. A lot of perfectly competent sparx cannot follow the logic path of a central heating system - especially when they get into zoned underfloor, and manifold units.

I find it helps if you can visualise the plumbing, as you would a circuit. You then have a better idea of what needs to happen to make things work. BUT, and this can be the problem, if you get 1 bit of the logic path wrong, very weird things can happen.

As an example. A recent job had the "grey" cores of the zone valves connected to the brown cores of the same valve. Although the system switched on as it should, valves would "lock on" in the same way you will "lock on" a contactor through a latching contact. So valves would open when demanded; they just wouldn`t close again.

Dependant on the system in use, it can be awkward to know exactly what is required.

So, to answer your question, I price CH wiring seperately, and don`t carry it out on a rewire unless it is requested or necessary for another reason.

KME

 

[green-hornet]

Is there any smilie programers on forum who could do a "over my head avatar" please?

I know what your saying KME, I have been called out so many times where people have had single zone senders trying to multi zone, wiring has been perfect. just wrong hard ware fitted for the job.

 

[kme]

Peeps seem to think that CH wiring is easy. It isn`t. It is much harder than house wiring - the hardest thing you usually have to work out is I/M switching. A CH system can be so many variants, especially with the new solar (wet), zonal systems, thermal stores; which mustn`t be allowed to get too hot, etc, etc. THEN you`ve got "custom systems", which the plumber or householder have designed themselves.

You can even have the issue I just had in my house. The rads on the ground floor have a) timeswitch control of CH, and B) programmable thermostat in the lounge (LV switching only!). When the old boiler went t1ts up, I replaced it with a different make, which would only accept 230V switching (the old boiler had no-volt switches for CH and DHW seperate - the new one just want a "demand" signal at mains.

So I had to devise a system to provide what the boiler needed, whilst not throwing mains voltage at my poor LV timeswitch. Cue 8 pin relay, and lots of head scratching - and I designed & installed the system in the first place!

 

[PIP IOM]

try and get hold of a mega-flow installation manual. It's the easiest to understand regarding S plan/Y plan etc. Mine is nearly worn out from constant use (simple diags) use it lots. Nice 6 x 4 adapt box/20mm stuffing glands/wago's/3 core/5 core H/R flex and Bob's your proverbial. Much better than wiring centre pattress jobbies.

 

[kme]

I know the one you mean Pip - they are handy diagrams - as long as you`re doing a "standard" S/Y plan, etc.

The point I was making is that the CH installs seem to be getting far more involved & complex, many times a "custom" install, where the "wiring diagram" has been drawn on the back of the invoice, by someone in the wholesalers : headbang

 

[Andy™]

generally re-wire supply to heating, but no futher, unless requested

 

[wozz]

I know the one you mean Pip - they are handy diagrams - as long as you`re doing a "standard" S/Y plan, etc. The point I was making is that the CH installs seem to be getting far more involved & complex, many times a "custom" install, where the "wiring diagram" has been drawn on the back of the invoice, by someone in the wholesalers : headbang

agreed, but if you contact honeywell and say you are using their products they will knock u up a wiring diagram. Had them make ones to include shunt pumps and SPDT relays where needed.

 

[jl-heating]

ignore the heating and just supply a feed to the existing fuse spur. (replace spur usually)

 

[Lillpete]

I would give it a new feed but wouldn't rewire it unless there was a problem with it

 

[a1]

Is there any smilie programers on forum who could do a "over my head avatar" please?

How's the one in the attachment, for you?

 

[Apache]

I like that - Admin