wiring in 6kW electric boiler

[Mattg4321]

Yes you can do that and the pump will run continuously 

[Tom]

2 hours ago, Mattg4321 said:

Yes you can do that and the pump will run continuously 

Cheers mate, took the plung and did just that. Got the Grundfos pump set at "Constant Pressure 3 - Max". Sounded like a jacuzzi in there for a long time but now settled down, think the auto air vent has done it's thing.

[Tom]

Still only 1-1.5L/hr in each of the 11 loops though. Should it be more than that?

Boiler set at 50deg, mixer vallve set at 35deg, temp in top manifold hovering around 20-25deg and return about 15deg

[Mattg4321]

From memory that sounds roughly correct I think. You should probably have more flow through the longer loops than the shorter ones though, so the system is balanced. You can adjust via the flow meters. 

[SteamyTea]

A litre of water has a SHC of 0.0012 kWh for each elevated ⁰C.

If your mean temperature difference is 7.5⁰C, and your flow rate is 1.5 litres/hour.

Your power delivery, per loop is around 13W.

 

1.5 litre/hour seems quite low to me. Or should it be per minute.

Changing to minutes would make your power delivery 60 times larger, about 780 W.

Edited December 26, 2023 by SteamyTea

[Tom]

10 hours ago, SteamyTea said:

1.5 litre/hour seems quite low to me. Or should it be per minute.

Changing to minutes would make your power delivery 60 times larger, about 780 W.

Ah yes, litre/min was what I meant. Think you'd get more heat transfer by convection at 1.5litre/hr

[Temp]

On 25/12/2023 at 08:27, Tom said:

Thanks @Temp, is it just a matter of putting a 13A plug on the pump wires and plugging in? Happy Christmas by the way!

 

Sorry I've been away from the forum. 13A fuse will work but is too high. I think most heating pumps are <250W so a 3A fuse should be plenty.

[Tom]

2 hours ago, Temp said:

 

Sorry I've been away from the forum. 13A fuse will work but is too high. I think most heating pumps are <250W so a 3A fuse should be plenty.

Roger that, thanks mate. Will swap out for a lower rated fuse.