Outside wiring.

[SurreyPlumber]

I am putting a quote together for a new boiler install and the only way to run a pump overrun is to feed the cable from the airing cupboard, up into the loft and then drop down an external wall to connect into the PCB of the conventional boiler.
I am going to run it behind a soil pipe so it won't look too bad but I need to know if this cable needs to be UV resistant or protected in any way as it is going to be exposed to the elements.
Thanks in advance guys!

 

[Steve]

Run it in plastic conduit (round conduit, not trunking), normal cable. Use appropriate fixings on the conduit to keep it all together.

 

[oharaf]

Are you sure there are no internal routes, I find this hard to believe. If not then as suggested by Steve Conduit is your solution, seal all the joints and consider small drainage holes in the bottom of the drop and the return incase of any water ingress later

 

[SurreyPlumber]

Are you sure there are no internal routes, I find this hard to believe

House is 35 years old, solid wood flooring throughout, new kitchen with floor to ceiling cupboards and marble everywhere.
What would have been useful is if the house builder sparky's had put some spare cables in the wall for a pump overun, because those boilers were readily available when this house was built. Usual case of F everybody that needs to work in the house after the builders warranty runs out.
Should it be rigid conduit or flexible ? If it can be either what generally looks better (I am guessing rigid).

 

[londonboy]

Or how about installing a boiler that doesnt require pump overrun

 

[SurreyPlumber]

I only install Worcester-Bosch and they require it.
To achieve it's SEDBUK A rating it needs the pump overun connected, and more to the point why spend all that money on a new boiler only to have the hot water sitting in the fragile ally or satinless heat exchanger after the CH or HW demand is satisfied. Surely it is better to have the pump utilise every spare BTU of heat that the boiler has produced, or maybe I just like to think that I do the job properly !!!

 

[Steve]

Flexible conduit will look poo snaking up the side of a house. Use black rigid conduit.
http://www.tlc-direct.co.uk/Main_Index/Conduit_Pvc_Index/20mm_Conduit_and_Fittings_Black/index.html this stuff.

 

[SurreyPlumber]

Perfect....
Thank You Steve

 

[flameport]

You will need some of this as well:
http://www.tlc-direct.co.uk/Products/MTGLUE.html
however this is the same stuff as used for plastic waste pipes, so you may have some already.