Pump over-run wiring

[Gromit]

Hello all, I'm a house-holder who's been given contradictary advice by Corgi registered engineers. I'm having a Gloworm Ultracom 30SXi system boiler with an indirect unvented cylinder fitted to my house.

Engineer one says that he has priced in for an installation of an additional cable to the pump which he says will be house in the airing cupboard upstairs and that this is known as pump over-run wiring.

Engineer two says that this is nonsense as the Gloworm Ultracom has an inbuilt pump.

I've called Gloworm who won't talk to me technically and will only confirm that there is an inbuilt pump and told me to take advice from a Corgi engineer who is welcome to call them. But I have two Corgi engineers who both radically disagree so I don't know what to think.

What a nightmare - all I want is a new heating system and someone competent to fit it.

 

[washer]

Not really a nightmare mate! They are both right in a way.

There are 2 types of Gloworm Ultracom's, a combination ultracom CXI and a standard ultracom HXI.

The combination ultracom has a built in pump, and does not require a seperate cable.

The standard ultracom does not have a built in pump and does require a seperate cable for the pump.

From your post are saying that you have an airing cupboard, so would assume you are having a Ultracom HXI, so would need to run a seperate cable to the boiler, from the pump in your airing cupboard.

 

[Gromit]

Thanks Washer. This Ultracom is a system boiler - an SXi. Ultracom2 sxi: System Boiler >> Glow-worm

I will have the unvented indirect cylinder located in a cupboard upstairs. From the attached I've downloaded the instructions and there is a pump shown in the diagram so does this negate the need for a pump connection to the airing cupboard?

 

[mikeygas]

A system boiler has the pump inside the boiler, so a pump overun is usually built in as standard.
As you are having a new system put in, your boiler requires a permanent live and a switched live to operate. Previously it would have required just a switched live which comes from the wiring centre in your airing cupboard (or via a junction box in the most awkward inaccessible place know to man!). It sounds as if the first engineer is suggesting that he runs a permanent live cable from the airing cupboard wiring centre to your boiler.

 

[Gromit]

Thanks Mike. The controller is located a few feet away, so can the permanent live be taken from the controller? The first engineer hasn't even been to the property and told me that he preferred to first quote over the phone (perhaps this has something to do with me asking to see his Corgi card when he turned up).

 

[mikeygas]

You are best getting the second engineer around to take a look as regards to the difficulty of getting a hard wired cable back to the airing cupboard. The best practice is to have everything wired from the wiring centre, but in my limited experiance I've seen perm lives nicked from everywhere.

 

[Gromit]

Thank you. I'll have a chat with him. I'm a bit paranoid as conflicting advice for someone like me who knows nothing about this subject is a worry. The route to the airing cupboard is going to involve a lot of destruction. Although not ideal is it ok to go from the programmer?