Re:12Kw Electric Flow Boiler

[Steve Flex]

Hi All,

Anybody have any experience regarding a Heatrae Amptec 12Kw electric flow boiler with control timer. I have been asked to install the above along with a plumber friend. I have checked the demand on the installation,which is ok, as it will be pulling a good 50A when going. It will be a 10m run from the consumer unit to the airing cupboard. I have done the calculations and it will need to be run in 10mm. The thing is the installation guide dosen't mention a contactor, which I think is necessary. I am thinking a 6A mcb to run the timer via contactor, at least a 50A mcb to run the boiler via contactor. I haven't had much experience with contactors, any ideas? Oh, yeah and there is only one space left in the consumer unit!

Cheers

 

[Guest123]

Re: 12Kw Electric Flow Boiler

Sorry to jump on this thread but as we are discussing boilers.Has anyone wired up any Nu Heat specifically "energy master thermal store cylinder with ground source heat pump ". I am just trying to get my head round it got the plans and relevant info .Has 12kw and recommends a 50 amp mcb but where is this fed to the heat pump itself and there are also fused spurs for the elements and pumps .(with me so far)and manifolds .would these be run separately on radials or all off the 50amp s will ring tech support in the week i am just trying to envisage the finished article so as not to miss anything out .Any help appreciated Scott

Hi there.

All the ground source heat pumps I've done in the past for Nu-Heat, have been manufactured by a company called - Ice Energy.

I have to say they are really quite simple to install depending on wether its running central heating (radiators) and hot water or underfloor and hot water.

The biggest problem you're likely to have is providing the supply to the heat pump itself as it is usually a minimum of 63A for single phase i.e 16mm t+e plus 10mm earth run as a seperate sub-main and not from any other c.u.

Three phase is different, i.e easier to split the load over the three phases hence smaller rated supply but possibly in s.w.a.

The only control wiring that needs installing before you actually connect up is

1. outdoor sensor (should be on North facing aspect) - 3core cable I used arctic grade 3 core flex.
2. room sensor - 5 core cable I used standard 5 core flex usually in hallway away from heat sources (radiators) etc
3.You may (depending on system) have a 3 port zone valve to wire back to heat pump - 6 cores required, 2x3core flexes (Heat resistant)
4. Circulating pump - 3 core heat resistant flex

All other control wiring can be done before switch on as its in or next to the heat pump - flow sensors, thermostats etc. Best to check with heating engineer about positions of valves, pumps etc also type of system i.e rads/underfloor

If underfloor then you will have a seperate manifold which will need supply to activate zone controllers and possibly another circulating pump. This would be sepearte from heat pump though and could be run as a 16A radial from any c.u. It should come with it's own control box.

Hope this helps, If you need anything else just ask.

Cheers

 

[Scott F]

Re: 12Kw Electric Flow Boiler

Nice one Lenny .I may well be back to ask for more infn my legend and plans it says low voltage screened do they mean heat resistant also its a new build thats why im eager to get it right .The mains is in one corner of garage heat pump in the other i was going to run heat pump off 50 amp cb as it only takes 43 amp its the 1140 ground source heatpump .Diolch Iechyd da

 

[mrloy99]

Re: 12Kw Electric Flow Boiler

Nice one Lenny .I may well be back to ask for more infn my legend and plans it says low voltage screened do they mean heat resistant also its a new build thats why im eager to get it right .The mains is in one corner of garage heat pump in the other i was going to run heat pump off 50 amp cb as it only takes 43 amp its the 1140 ground source heatpump .Diolch Iechyd da

Its unlikely you would need screened cable in a simple domestic situation.The sensors probably are 8-12volt.You can get small bore screened cable about the size of phone wire,or you could use screened fire alarm cable(with the foil in it)If you REALLY wanted. Or you could just keep them away from your mains wiring.

 

[Guest123]

Re: 12Kw Electric Flow Boiler

Hey mate.

The sensors only need an alarm sized cable to work as they are only 12V, the problem I had was the distance between the sensors and the heat pump which is why I plumped for 1mm flex to cover the VD.

If you only have a short distance to run then screened alarm cable will do.

Cheers.

 

[Scott F]

Re: 12Kw Electric Flow Boiler

Just posting to say Nu Heat came round and commissioned today , worked first time .

Don't you just love it when that happens.

So basically this is a thanks to Lenny and Mrloy for the input , nice one