ProDave

Is this liability insurance for a self build site you can't get? Or a structural warranty for the building?

Your reed switch is rated at 1 amp. Your light driver is rated at 0.65 amp. So in theory you might be okay. BUT that will be a switch mode power supply so the input circuit us usually a bridge rectifier then a smoothing capacitor. So on first power up there will be a high starting current to charge the capacitor quickly. It is likely that high starting current has welded the contacts of the reed switch. Seriously, i would look at a little mechanical switch of the type used for limit switches on machinery that will be activated when the gate gets to end of travel. Or hack the existing circuit to find a way of triggering a relay from the existing switch. Do you have a picture of the insides of the controller?

Assuming these are tall so you can't look down on them. Screw an L shaped bracket to the wall at each side, dead level with the top cross member on each cabinet. Put the cabinet in place, a single screw down through the L shaped bracket into the cross piece at the top of the unit.

That just strikes me of a lousy design.

And the repaired section of the bank completed. Land drain pipe still flowing.

No that is too specific. Yours is a make it up as you go along box of terminals for a one off system.

The varilight one is something altogether different.

No, that is what you would use if you were having lots of individual zones and individual actuators for each pipe loop. You just want to join together the two motorised valve cables, 2 thermostat cables, a cable to the pump, a flex in providing power and (still to be determined) how to connect to the RTC6. Something like this https://www.toolstation.com/drayton-wiring-centre/p56309

Good find, but THE PRICE !!!!

To make it work you need a junction box to connect it all together, I would start with a standard central heating "wiring centre" which is usually just a plastic box with a 12 way terminal block inside and lots of cable entries. I am hoping that one of the many forum members familliar with the FTC6 will answer what it's call for heat input is.

So you have one motorised valve per manifold but only ONE pump that serves both manifolds. That complicates the issue. What is the call for heat input on the FTC6? Does it have to be a volt free contact or will it accept a switched 240v ac input? The logic is: Basement thermostat energises basement motorised valve when it wants heat. Ground floor thermostat energised ground floor motorised valve when it wants heat. The feedback contacts (orange and grey wires) from both motorised valves connect in parallel and will turn on the pump when either floor is calling for heat. Where it will get complicated if the FTC6 insists on a volt free contact you will have to use a relay.

Yes you want to specify "loop at switch" Wiring regs don't specify which method to use, it is choice of the electrician or the client.

If anything I would say mine defrosts more in DHW mode as it is generally working harder then.

The worst time for icing is when the air is a few degrees above freezing, the heat exchanger will be colder and in this case below 0. Once the air gets below 0 for any length of time there is little moisture left in it, so almost counter intuitive, there is much less chance of icing. I have an older version of the monoblock ASHP and there are no user adjustable parameters relating to defrosting. And nothing published about how it decides when to defrost. I would be inclined to just let yours get on with it if nothing else to see if the defrost function works.

4 gang grid switch is your only answer with one fitted with a blank. I have never seen a 3 gang switch in a 2G wide front plate. Or if going for new dimmers, just buy any make of new dimmer and swap the modules over onto your old front plate.

My No 1 tip is do it as a warm roof or hybrid roof. So air tight layer over the top of the attic joists (roof stripped completely) external insulation over the top of the joists, then batten counter batten and tiles or do the rolls royce and an in roof PV system. Take the insulation right down to the eaves don't faff about trying to exclude the eaves space from the insulated envelope. You might want a SE to check the existing attic trusses are ok for a heavier roof tile and PV.

I thought the conversion from m3/m2 to ACH was very approximately 1:1 but there is no simple universal conversion because it depends on the geometry of the house, i.e is it single storey, 2 storey, vaulted ceilings etc. If it really was divide by 20 them my 1.4 m3/m2 would be 0.07ACH. No way is that the case.

And sometimes it can be warmer here due to the Foehn effect

I would say 15mm is pretty insignificant for a 175mm joist. The important point is drill the hole on the centreline.

Hillockhead is not far from me, on the north coast of the Moray Firth. It's one of the weather stations I use when checking if it's good sailing weather. Contrary to popular belief but sun does shine up here. The reality is the main difference in the weather up hers vs down there, is here it is colder and windier.

It's an electric fan heater. If it uses half the electricity of another heater it will take twice as long to heat the room and cost exactly the same. If you want an electric fan heater, just buy the cheapest one you can. Trying to claim it is more efficient than others is snake oil. EEK I just looked at the prices. AVOID.

You are slightly confusing the discussion by talking about a "reed relay" Those do exist but they are not what you want. you want a "reed switch" that is just a switch that closes when it gets near a magnet. You might find the contact rating a bit low for your needs so you might need to use the reed switch to switch an conventional relay to turn the lights on. My personal preference in that situation would be to reverse in. Reversing out you are putting the rear end of your car in danger before you can see if anything is coming. That is actually safer at night because you hope they would have lights on so you should see someone coming. If you were building that house now they would insist you had turning space so you could enter and then leave in forward gear.

With mine, an LG ASHP I turned off all the settings in the heat pump to automatically use the immersion heater. A well respected former member did a very good analysis that if you are on treated mains water, you can be sure there are no bugs in the water supply, and if the cylinder is unvented, no way for bugs to enter, so no need for a legionairs cycle. Different matter if you are on a private water supply or have a vented water tank fed from a header tank. I can still turn my immersion heater on manually should I need it, and in any event surplus solar PV automatically goes to the immersion heater.

Just watched this episode. I don't have a problem with the size if it. If someone can afford it and that is what they want best of luck to them. Although it took longer than their plan, there were not any major blunders with the build. But what did get me quite angry and shouting at the television was this Passive House Plus. The house has to generate 4 times the power it uses. That's a very laudable aim and one you would hope would be achievable. And it is the achievable bit that got me angry and shouting, because where I am, and in countless other places it would simply NOT be achievable. Not because I don't want to, but because the DNO would not allow it. They did touch on this in one sentence right at the end, the DNO export limit in this case is limiting them to about 2.5 times what the house uses. That is way better than what I am allowed, but still it shows the infrastructure and the red tape is holding back proper domestic scale self generation. And the £100K plus cost of the roof PV system would be another deal breaker for me. If programs like this keep on showing that domestic scale self generation is being hampered by an under funded under capacity grid, and stupid red tape, then perhaps, just perhaps the situation might improve.

These Horstman timers can be wired in a number of ways bepending if you have 1 or 2 elements and if you have a switched off peak supply. But the general principle is you want the tank heated between about midnight and 7AM during the cheap rate. The boost is only there in case you have used a lot of hot water and ran out, and will be charged at the peak rate. I would set your normal timer times from say 3AM to 7AM to get the latter part of the off peak time, and then only ever press the boost button if you have used all your hot water and need more before the next overnight charge.