Central Heating control cable from Screwfix

[Alan]

I'm putting together a Screwfix order with loads of bits to convert my CH system from gravity-fed to fully pumped over the Easter weekend. I will need a load of multi-way (5way?) cable to go from the motorized valves, programmer, thermostats and boiler back to the 10-way junction box. Various search terms arn't finding the cable on Screwfix's website. Does anyone know if they stock it and what they describe it as or a part number?

I also can't find 22mm > 3/4" adaptors (solder preferably). Surely they stock these?

Many thanks,

Alan.

[stevelup]

I don't think Screwfix do it...

TLC do 4, 5 and 7 core

[Wingedcat]

Screwfix don't sell imperial adaptors but plumbers merchants do. Some say 22mm and 3/4" are interchangeable, providing you use a lot of solder. However I tried this method and failed! (The joint leaked everywhere).

You can however wedge 1/2" pipe into 15mm fittings - even I managed this okay.

Anyway 22mm > 3/4" adaptors are available online at

for

54p each + VAT or at a sky high fee (from memory, =A31.50 each I paid I think!) from your local plumbers merchant.

Luke

[Alan]

> Steve

Thanks. I tried a bit of googling and found that Toolstation stock a 6 way cable in the correct core colours cleaper than TLC's 5 way (Stock code

97675 - £26.96 for 50m)

I notice the also have 2 Port Motorised Valves for £28.70 - considerably cheaper than the Honeywell's from Screwfix at £43.99 - however they don't specify a brand. Are these likely to be cheap for a reason and best avoided?

Alan.

[Ian_m]

Noticed my B&Q sold heat resistant 5 core cable recently at a rip off, but available on the shelf now price.

[TheScullster]

"Alan" wrote

Watch out for Part P. Applicable to power or control wiring for new CH system.

Phil

[Alan]

Ah, but it's not a "new" CH system, just the old one modernised a bit ;-)

Alan.

[Roger Mills]

Yes, officially it comes under the dreaded Part P. But violations are unlikely to be detected unless you succeed in burning your house down.

[Bob Eager]

I had trouble getting what I wanted in less than a full reel. In the end I got it from the local plumber's merchant!

[Owain]

But if he burns the house down there won't be any evidence, will there?

Owain

[John Stumbles]

They're Tower brand which is generally crap. I quite like the Sunvic ones from B&Q - not too expensive and easily removable (pull-off) heads so you can easily reverse them and quickly check the working of the wet and dry parts.

[John Stumbles]

IIRC Toolstation also do 22mm x 3.4" but only in packs of 25 or so.

[Dave Plowman (News)]

I'm not sure I'd use multi-core flex for all that unless the components are close. For things like the programmer and thermostat which are usually some way off, Triple and Earth can be a better bet as you'll probably need a drum of that for other uses. Multi-core is only really needed for extending things like 3 way valve wiring, or to the actual boiler.

[Lurch]

On Thu, 29 Mar 2007 11:06:22 GMT, "Alan" mused:

The valves will come with flex attached.

The programmer would be better wired in fixed wiring cable, like twin and earth and 3 core and earth.

See programmer.

See thermostats. Add a flex outlet and pattress to near the boiler for transition from fixed wiring to flexible.

If any flexes aren't long enough then a flex outlet by it and an extension in twin and eareth\3 core and earth is fine. Excessively long runs of flexible cables are deemed to be a bodge.

[Alan]

Interesting, I'd assumed using twin & earth or 3 core + earth would have been considered the bodge! The valves will be within a meter of the main junction box, but boiler, stats and programmer won't be. I do have a reel of 3 core + earth in the garage however, so I could just use that then.

Thanks,

Alan.

[TheScullster]

"Alan" wrote

True, but I used the "new system" argument to get a certificate for my install when it was done recently just in case.

Phil

[Lurch]

On Fri, 30 Mar 2007 00:11:45 +0100, "Alan" mused:

As long as final connections are in flex then no bodge.

Why not.

[Roger Mills]

Depends on how thorough a job he makes of it!