Finally got it up and running

[Beelbeebub]

1 hour ago, sharpener said:

 

Unfortunately that seems to be the case, even the 3.5kW Vaillant can draw up to 14.3 amps (it is the same unit as the 5kW but with the output capped).

 

 

However you would probably want a separate circuit, just as you should have for a boiler or an immersion heater. But an existing boiler radial circuit would do for an HP up to 7 kW. With inverter drives you do not need to allow anything more for inrush/motor start.

 

A bigger problem though is that with an inverter drive you need to fit a Type B RCD and this is not allowed to be behind a Type A in your existing consumer unit, as discussed in an earlier thread. They are expensive and not available for all types of CU (and that includes Crabtree and Wylex until 2025). So in practice you may end up needing a new garage unit installed with Henley blocks. As I discovered, it becomes even more complicated with a battery setup as well.

 

 

 

The RCD bit might be the killer. 

 

The current draw is not necessarily that high. I think alot is in how the inverter is set up. 

 

The new Grant r290 units draw considerably less. 

 

 

[ReedRichards]

3 hours ago, mk1_man said:

 

The insulation is Primary-Pro, brilliant stuff and possibly the best for external use.  I am however going to be putting a sort of lid over it made up of some 40mm xps foam board I have. Conscious of need to maintain air to the anti-freeze valves.

 In winter the field mice like to take up residence in my loft.  There isn't much to amuse them up there so they like to chew on any foam pipe insulation that they can find, whereas so far they haven't touched the aluminium-clad stuff.  I was concerned that your insulation looked too much like the type that is susceptible to rodent damage.    

[mk1_man]

On 26/09/2024 at 13:18, crispy_wafer said:

QQ, How did you deal with the insulation through the wall?  I see they have plastic interface thingies for tidying the hole up, in two minds as to whether they are worth it though.

 

Hi, I just ran the primary pro insulation straight through the cavity wall. Its a nice tight fit and creates good seal. I have seen the plastic tubes and finishing bezels?   Don't think they are required myself.

[SteamyTea]

On 26/09/2024 at 13:49, Beelbeebub said:

just the pin plug that limits to 13A.

Continuous usage rating is 10A.

[Beelbeebub]

4 minutes ago, SteamyTea said:

Continuous usage rating is 10A.

So a 4kw unit would just about be doable, possibly a 6.5kw depending on what the continuous vs surge currents are. 

 

Prob enough for a flat or a reasonably insulated terrace. Two units would do a lot of houses and 3 would do most. 

 

But it would be a big shift in mindset. 

[sharpener]

2 hours ago, SteamyTea said:

Continuous usage rating is 10A

 

Used to be good for 13A and would run a 3kW fan heater for hours on end. Now downgraded and downrated so a granny lead will only charge a car at 2.2kW.

 

Yet they are deemed a suitable way of conecting a permanently installed undercounter oven. Son recently had the plug melt and burn out completely and had to replace the socket as well. Cause seems to have been poor contact at one of the fuse clips.

 

So I wouldn't want a permanently installed piece of kit like an HP wired in with a 13A plug and socket, 16A commando perhaps.