ProDave

Yes they are my go to choice for basic stuff. They are cheap but good quality. A lot of our house has them. One of their hidden tricks, id the light switches you can remove the switch modules, handy if you want to mix intermediate switches with ordinary switches without having to go to a full grid system.

For me, the mention of "APP" turns me off. If I want to do this sort of work I want a big screen, and proper multi window OS and proper input tools like a mouse and a real keyboard. i.e. I want a fairly decent computer. APP to me means a phone, the very last tool I would choose to use for such a task. I manage such tasks quite easily with a web browser, a spreadheet and a word processor.

What fuel is the boiler? Unusual to not have an indirect hot water tank heated by the boiler.

I always feel it is a shame we are all so poor that we even have to consider storage heating as a way of getting it a bit cheaper than real time electric heating.

The only bit that needs knowledge is the initial setting up and comissioning, getting flow temperatures and flow rates right. After that is all done you just leave it to get on with things, you never need to tinker with it. Just like any other central heating. In the heating season I never touch any controls and the house is always the correct temperature. That is a far cry from storage heaters when you need to look at the weather forecast each evening and see that it is going to cool down tomorrow so you need to increase the input control to put more charge into the heaters tonight to be ready for that.

I do wonder if a storage heater might actually make more sense in a modern low energy house with good insulation and air tightness. My own house heats up slowly and cools down slowly. So an injection of heat overnight and it won't have cooled down much by the evening. Some I believe do that charging a heavy insulated slab overnight. But a heat pump is still way better. I used to have storage heaters in my old 1930's semi. Absolutely hopeless. The house leaked heat so quickly that it really was of the type that needed constant heat input when you wanted it to be warm, and it barely had any left in the storage heater by the evening. I did find an LPG gas fire was good for topping up the heat in the evening. And I have lost count how many people I have had to explain how they worked. I turn up to a reported fault of "heaters not working" and when I get there, I see they are turned off at the wall. "Oh i turned them on waited a couple of hours and they were still cold, so I turned them off again" Bangs head against wall.

Why don't you use the appropriate beads and do the corners yourself?

In the real world the 4mm cable or that in parallel with the 2.5 will be okay. At both ends, join those to a short length of 6mm and connect that to the bits of kit. In the event of a warranty claim, they are not going to pull your house apart on the suspicion it may not be 6mm all the way. Just don't make the transition obvious at either end.

I would just build up the ground level by 4cm. It only needs to be built up in one place. 5cm in case any inspector has a wonky tape measure.

Is there anything restricting the depth in the cavity? the time I find the lugs don't click into place are when the back end of the yellow lug has hit the back of the cavity. Get a long flat screwdriver behind the bit sticking out either side of the screw and you can sometimes pull or lever it forwards that last bit it needs. I doubt all your cut outs will be this thick, how many have you cut so far? P.S I usually do the cut outs before the spread arrives.

For just 2 resistors it simplifies to Rt = (R1 X R2) / (R1+R2) When I get time I will look up the ohms per metre of the 2 cables and try an example. I don't think you actually need the parallel resistance. All you need is the ohms per metre of the 2 cables and then work out the current through each cable when in parallel at a combined total of 32A. You are looking to see if they share the current in proportion to their max current carrying capacity or of one gets overloaded.

Putting two different size cables in parallel may not work as expected. My question to the battery manufacturer (it might be in the specifications somewhere) is what does the maximum current carrying capacity of the cable need to be? Depending how the 4mm cable is installed, i.e is it in contact with insulation, encased by insulation in free air etc, could be anything between 22A and 37A

I would want to be taking a section of the slab up and replacing the lot in new plastic pipe. Including the run under the foundations. Then you can get it as you want in the place you want.

I did mine in 22mm but had issues with water flow rate which I solved by fitting a second circulating pump. I do have all my dad's old plumbing tools including his Hilmor pipe bender that has 15, 22 and 28mm formers, and (it is old) I still have the imperial formers for it. You could have just done straight runs and soldered elbows to avoid bending?

Can you clarify, are you talking about a split unit? If so who did the Fgas connections and charging? If a monoblock, what is this big indoor unit you talk about? A hot water tank? I did my own with a LG 5kW monoblock and found it easy from a plumbing point of view, with a Telford stainless heat pump hot water tank. The wiring a little harder as the unit lacked a few fundamental control inputs that I had to work around. Complicated - yes. the supplied control panel which is supposed to do all you want in terms of controling it and setting on / off times is WAY too complicated for the average person. I regard that as just a means to enter parameters and check for faults etc. For the "user" controls I grafted in a perfectly standard central heating programmer so you can set heating and hot water on off times using a standard interface just like if you were using a gas boiler. One of the BIG problems holding back installers, and in particular deterring present installers of boilers, is the electrical controls are way more complicated and so different from one manufacturer to another. What is needed is a simple standard like with a gas system boiler, "call for hot water" and "call for heat" are all that is needed and presented in a standard form like gas boilers. The Grant heat pumps are the only ones I have seen so far that achieve this. From a plumbing point of view, a heat pump is just like a system boiler. It heats water, just flow and return connections. That bit is easy.

Re caravans. Find your local dealer, there is a steady supply of second hand ones coming off holiday sites when they get too old. The advantage of buying from a dealer is they usually have several to look at and choose from and they have the transport to move them, usually included in the sale price. We paid £4K for ours, it was actually still on the holiday park when we viewed it, and we chose it for it's unusual layout with the living room in the centre and a bedroom at each end which suited our site well. So it came on their wagon straight from the holiday park to our site. You can buy privately but you have more work and travelling if you want to look at several, and you may find transport harder to arrange, our local dealer will only move 'vans they are selling or buying, they won't just move one privately sold. On our first build when we sold the 'van at the end, I think the closest transport company the buyer could find that would move it was somewhere around Elgin.

When you say stays on, you mean glows VERY dim and can only be seen when it is dark? If so capacitive coupling between adjacent L cores in a 3 core 2 way switching cable can cause this. This can sometimes be cured by reconfiguring the usage of the 2 way switching cables to put the switched L cores either side of the earth. Or fit a snubber in parallel with the light. Or just try different types of light bulb. If it is staying on at full brightness then you have a different fault.

Wet UFH downstairs here. Upstairs has wet UFH in the bathrooms just to stop the tiles feeling cold. I installed cable and back boxes to power a panel heater in each bedroom. Never got used, cable not connected either end, cost perhaps £20? I was only ever going to buy the heaters if we found they were needed, and they were not.

More pictures please of any other plumbing stuff near the UFH manifold. There is no sign of a pump or blending valve, so chances are it is circulating water far too hot through the UFH pipes. And there should be a motorised valve or 2 to switch between hot water and heating. As many pictures of all the plumbing bits please. And there should be an electrical box near the manifold follow the wires from the actuators on the top and post a picture of that. Initial assesment, the original installer didn't have a clue. You are going to probably have a steep learning curve or find someone that does understand such things to sort it out.

Good point, there is mention about starting current an mention the compressor may not start if too much cable resistance, suggesting it is not an inverter drive. More reason to reject it.

As long as you apply for the self build exemption before you put a spade in the ground. That bit is important.

I take it this plot of land does have some form of planning permissions? You probably want to resubmit planning for the house you want, and include on that temporary planning for a static caravan as accommodation while you build. You can buy a second hand static for not a lot of money. Many on here have been temporary caravan dwellers, including me (twice)

I tend to agree. The manual talks about tank temperature sensor and control of valves etc but then the wiring diagram does not show where they connect to. I would go ahead with your plan to return for a refund as "not as described" I would be tempted to connect power to it and power it up. It won't run for a whole host of reasons but I would be interested if the controller display matches what is shown in the manual.

Can you post pictures of ALL the PCB's inside the unit and all the connectors on them please to see if we can shed any more light on it. If you have an electronic copy of the manual can you post that as well please?

If you have bottled LPG you will find a very similar set of restrictions on where you are allowed to site the bottles in relation to drains, air bricks, or other openings, opening windows and doors etc. For all the same reasons, to prevent escaping gas entering the building.