ProDave

Try it yourself first, I was surprised I can do it. Don't ask me how it works, but it does.

I am keen to see how this back to back WC into a single outlet works, and does it suffer the "swapped contents" problem?

I was visiting a relative recently, she had an extension several years ago with UFH in the extension. But the UFH "never worked properly" so after a couple of years, she had radiators fitted in those rooms and gave up with the UFH. I had no part in that discussion or decision. But following that visit it seems her boiler is set to heat "hot and hard" for 1 hour at a time. No wonder the UFH failed to do anything sensible.

A valid point to make here even stronger, is a Time Of Use tariff should only be used by someone who understands the different charges at different times of day (and with some tariffs they vary day to day) and then actively manages their energy use to consume as much as possible in the cheap times and as little as possible in the expensive times. If you don't do that and just "use it when convenient" I really don't think a time of use tariff is for you.

I don't know your particular heat pump, but there should be a way of setting a timer so it only heats hot water at certain times, and you want to set it so that it does NOT heat the hot water between 4PM and 7PM. Then you will just be using the hot water from the tank and it won't re heat it after use until the expensive period has ended. Same could apply to heating the house, set it so it does not do that between 4PM and 7PM. See if the house keeps warm with the heating off for those 3 hours, hopefully it will.

You don't need a servitude right for anything in your own garden. A servitude right gives you a right to do something on other people's land, like the example of my previous house where it allowed us to install a drainage field under the adjacent farmers field. That servitude right was presumably negotiated by the owner before he put our plot up for sale. Be very careful here, you have a system that might work now by discharging to somewhere unknown (I doubt that 2M pipe is enough) but you don't appear to have any right to do anything outside your own garden, IF that system ever fails, then you have no right to do anything on other land to fix it, or install any replacement system. Your own small garden will NOT be enough room. This is where you need a good solicitor that understands these things. He should be insisting the vendor gets busy and negotiates a servitude right with the owner of the adjoining field where this tail pipe leads to. I hope you have not yet concluded the missives?

With such a peak usage at the most expensive time, 4-7PM I suspect you might be better not on any form of Time Of Use tariff and just be on the standard fixed rate all day tariff. Time Of Use tariffs only make sense if you can use most of your energy in the cheap times and as little as possible in the expensive times. For most people with an all electric house it is impossible to avoid usage in that 4-7PM slot. P.S just "having a shower" in that peak time need not use any energy. The hot water comes from your hot water tank. Just adjust the timer for the water heating so the ASHP does not immediately start re heating the water until after the 7PM expensive period finishes.

Not in my house. Council tax is more than twice my total energy costs. But unlike energy costs I can't do anything to reduce it or swap suppliers for a better deal.

For the record I installed UFH in my first self build 23 years ago. There was no forum to discuss things with then, I was flying on my own. We installed UFH upstairs and down, each room on it's own thermostat and zone, driven from an oil boiler. No mains gas available and I had not heard of heat pumps. That system is still working. It has had normal maintenance, several motorised valve actuators replaced (WHY are they the most unreliable bit of a heating system) One pump replacement, and one thermal mixing valve replacement. And normal boiler servicing. What I learned from that is many (most) system designers are NOT experts. We were advised to have UFH pipes in the downstairs hall AND the upstairs landing. The hall rarely called for heat and the landing NEVER. That system should go on forever if you can get parts, when the mixer valve failed, it was hard to find a replacement, it is not a design of manifold that is for sale now.

Tail Pipe is the wrong thing to be asking about. It is the drainage field or infiltration field that matters. I don't literally mean a field, that term refers to an area of ground that has a network of perforated pipes set on stone buried under the field. In the case of out last house the deed of servitude indicated the position and size of that under the adjoining field. The good news is as long as it actually works, and it does drain somewhere, SEPA are exceedingly unlikely to ever bother you. In spite of what they might say, the reality is they are not taking any enforcement about people here with septic tanks discharging directly into the burn. But the bad news if you find it is not draining away then you will have problems sorting it out. Worst case is you have to dig up the field where your tail pipe leads to and re lay the drainage field. That will test if you really have a deed of servitude, so now is the time to properly get to the bottom of that. Make your solicitor earn his money. Do you have direct access to the watercourse or would you have to run a pipe over other peoples land to get there. It is worth exploring that so you have the option to upgrade to a treatment plant discharging to water. That is SO much better, P.S. the outflow from a septic tank will stink. The outflow from a properly functioning treatment plant should be a clear and odourless liquid.

Seriously, a 90 year old house will be full of cracks and gaps that a mouse can get through. They can get through the holes in an air brick. You will NOT stop mice getting into that house. Get some poison or your preferred type of trap and treat it as something you have to do living there. My present house built to be air tight, is the first house I have lived in where so far the only mouse we have had in the building got in through an open window. Otherwise they don't get in here.

A septic tank should not discharge to a watercourse. But of course in the real world we all know many do. The best upgrade you could do is replace the septic tank with a proper treatment plant, discharging into the watercourse. You will need planning permission, a building warrant and a permit from SEPA but well worth it.

How hard depends on the type of ground to dig, depth, and type of pipe that needs capping (clay or pvc)? But even of your visitor is getting into your drains, how is he getting into the house from there?

That should all be fine then. The issues can arise with PME / TNCS earthing by the supplier that has a known failure mode that can raise certain dangers if exported outside the house and that does not seem to apply here.

What type of earth does the main property that is feeding this small CU have? You say this CU has it's own earth rod, so are you saying it has a connection the the main house earth AND it's own earth rod connected? Is the metal lamp post supported by being buried in the ground?

As above questions a LOT more information needed. How old is the property? How big etc. And your approximate location, Is the Heat pump new? Does it replace a previous heat source, e.g. a boiler, if so how much did that cost? It is not easy to apportion heat pump consumption from a total electricity bill, I know exactly how much mine uses only because I chose to fit my own electricity meter to record just what the heat pump uses. The best you can do is compare the daily usage now, with daily usage in the summer, if you do that you get an idea how much additional electricity is being used by the heat pump.

Have you looked at timber frame, with Wood fibre EWI as I have, the phase shift is about 13 hours, similar to your ICF figure. It is certainly provided a low energy and comfortable building.

And if you have PV on your roof, you can pretty much guarantee when you need to run your cooling system, there will be enough power from the PV to power it, so no demand on the grid.

I can't tell from the photo, Are the row of lights top left on the Unipipe box all light up, or is that just the reflection of the camera flash? What you should see is when the heating is on, and the room thermostats are turned up calling for heat is those lights will light up, and the corresponding actuators on the bottom row will be energised. Since there are only 6 actuators, I would expect only the first 6 of the lights on top left to me light up, the others not in use, which is why I think it is camera flash reflection making them look illuminated.

That is the critical statement. I doubt a single or even 2 panels in series would achieve the minimum voltage to start most grid tie inverters.

Domestic grid tie inverters generate a high voltage output so need a high voltage dc input to do that, hence it is normal to connect the panels in series. forget all you know about boat inverters.

You wire the panels in series. I have 8 panels on each string and 2 strings, one facing east the other facing west. With only 4 panels that may not work as each string may not achieve the minimum input voltage. What is limiting you to 3kW? the default domestic install is 3.68kW (the max without prior approval under G98) That is probably where there is most choice.

Check with the seller it is G98 approved, It should be at only 2 years old. Susprised they don't state that, Only 1 input so all panels need to be on one string. 2 inputs is better if you want panels on different facing roof elevations etc.

So because people cannot be educated to use wet wipes properly and put them in a bin not down the loo, we ban wet wipes.

For your DNO sign off, with a G98 inverter you will need to fill in a form and provide some drawings including location of equipment and a wiring diagram. as well as an Electrical Installation Certificate from the sparky. Make sure the sparky can provide the wiring diagram as well as the EIC. for G98 you notify the DNO afterwards. The G98 application is linked to your electricity meter's MPAN number. If as hinted both properties share a single supply and meter, you will only be allowed one G98 application. If you want solar PV for both, you might have to get a second supply installed so each building has their own supply and meter. If buying secong hand inverters, make SURE they are not so old that they pre date the present G98/G99/G100 types.