ProDave

Sorry I had my under floor heating manifold thinking cap on. For the flow manifold to get hot, there must be some flow, otherwise that would remain cold. So as @Nickfromwales says check the radiator valves are on. Try also turning all the downstairs radiators off, that might encourage a bit more flow upstairs to get it started if it is an air lock. If all else fails, turn all radiators off then upstairs rads just one at a time.

Try turning off ALL the other pumps, so you only have the manifold circulating pump running and see if that makes a difference (thinking if flow and return TO the manifold is piped backwards, or a pump is connected backwards, it will be fighting the manifold pump)

Seal PIPE to a snug fitting hole in the OSB layer. Insulate pipe inside and outside tight up to the OSB and seal around that as well. How are you going to use it for cooling? when I get around to implementing a cooling function it will be by way of a fan coil unit or 2. For this it will branch off from the flow and return in the plant room which is above the garage. This means cold water will never flow through the insulated pipes above the living room ceiling, they are only for hot water to the tank and UFH.

Can you post some pictures of your manifolds etc and any controls like motorised valves? Do you have individual controls for upstairs i.e. on a separate timer channel to downstairs? Can you hear the manifold pump running on the upstairs manifold?

Having lived in a 1930's house I know how much heat it needed thrown into it to keep it warm. What upgrades have you done to the walls and floor to improve it's thermal performance?

Is the root of the issue that your "25mm" battens are thicker than your "25mm" insulation? Just trying to understand what has happened, not having a solution, sorry.

What's that actuator head position on the left of the blending valve? Surely with a blanking plug screwed on, that will be shut?

You have just described yourself.

A couple of weeks back, I noticed there was nothing being diverted to my immersion heater. A quick check in the shed revealed the main inverter was showing "Grid disconnected" further investigation found the 32A mcb feeding the shed had tripped (but not the 16A inverter MCB in the shed) So I reset that and the main inverter powered up again. The cause of the trip was the little cheap Chinese inverter connected to my 2 spare panels had blown. Having failed at just under 2 years old I was not particularly liking the idea of buying another, but there is nothing else available anything like as cheap. So time to take it apart and see if a repair was possible. Inside a PCB mounted fuse was blown and some basic testing found that 2 of the transistors that make up the H bridge that synthesises the output waveform were blown, short circuit. So i ordered 5 of them from ebay from China for £5 They arrived yesterday and i fitted them and cautiously powered it up and it's working again, so this morning I put it back into service. It will be interesting to see how long it lasts before failing again. What I did notice is they were very short on the heat sink paste, with it only applied to one side of the insulating washer, so it's pasted up a bit better now.

Please tell me what EV I will be able to buy next year for 11p? (I'll get my coat)

I have not done it myself, but I have seen plenty of attic trusses cut to fit dormers and velux windows. Perhaps it needs the input of a structural engineer? They seem to usually put doubled up attic trusses either side of the window and frame the headers on site.

Linux is cool. And of you choose a proper version of Linux you get it without all the apple bloatware / restrictive software to cripple it.

Interesting concept but my thoughts: It's an odd size. big for a single car port but way too small for a double. Size dictated by panel size not "how big should a car port be" Construction looks flimsy. Standing on just those 4 legs with no bracing, I doubt it would survive the first Highland winter. The panels and inverter are worth about £2K making the car port structure to sit them on expensive in my book.

If you can, set up the washing machine etc in a temporary utility room in the barn. A WM running in a caravan has to be seen to be believed!!!! Best thing we did with ours was fit a wood burning stove in it. It burned almost continuously from November to March over the winter with the "beast from the east"

So you have a 3 phase supply. Good. Use a 4 core cable (Neutral, L1 , L2 and L3) And feed a 3 phase 6 way distribution board to split it to the 17 units 6 each on 2 phases and 5 on the third phase. 35mm will do for current carrying capacity but will still not be big enough to keep voltage drop within allowable limits. At full load of 16A per unit I am coming up with 85 square mm cable to keep voltage drop to no more than 5%. It would be even bigger if you were trying to keep voltage drop to the lower limit for lighting circuits. Your ONLY hope of getting it smaller is to do some diversity calculations to get the total load down to a LOT lower than 16A per unit.

I was thinking a collection of camping pods or glamping or whatever todays trendy work is.

17 times 16 is 272 Amps. No 1: That lot will not be powered from a typical domestic 100A single phase supply. No 2: It will be voltage drop that determines the cable size over that distance, and it will be a BIG cable. No 3 you would not normally export an earth over that distance so it would be 2 core cable and probably a local earth. This is a serious design issue and as a very minimum it sounds like you want a new DNO installed 3 phase supply as close tothese 17 units as possible.

Explain these bypasses please, if possible with a picture of your actual manifolds?

There is a house near here that has borehole water, the only time we encounter very hard water up here. About every 3 years I have to change their immersion heater as the water eats through the element, and each time I spoon a good bucket full of scale out of the immersion heater hole before the new one goes in. Each time the scale is level witht he heater element which probably contributes to the demise of the heater. Does anyone make an UVC with a large flanged access plate big enough to get in properly to de scale it?

Get everything connected to just your cheap 24/7 meter then call them to swap to a single rate tariff.

-10 night temperature is common here in winter and my ASHP still works okay.

At the moment you have something like 4 "supply" cables coming out of your collection of meters. If you switch to something else, there will only be 2 outputs if you choose E7 / E10 or just 1 if you go for a single rate tariff. So you will need an electrician to do some re connecting to ensure everything gets power from somewhere. You need to think about what you have and how you want it powered. e.g if you use storage heaters then you will really want to stay with E7 or E10. The Unique feature of your old "Total Control" system (I think it went under a variety of different names) as that as well as a normal daytime supply and a cheap off peak supply, it also gave you a "heating" supply that was on all the time and metered 24/7 at the cheap rate. That was useful for showers, and real time electric heating like panel heaters. you won't get that any more with E7 / E10

You will need one in the kitchen. TOP TIP: Aico make a combined heat and CO alarm in one package, perfect for the kitchen.

The only thing my BCO mentioned was if we abandon the balcony, then there would need to be another means of escape. There is in our case an opening window next to the door. If the door was the only means of exit from a bedroom then you would need the balcony in order to be able to use that means of escape.

I discussed this with our BCO recently. If we don't immediately build our balcony, an acceptable solution to BCO would be to fit banister type handrails across the inside of the door opening (it is an outward opening door). the door is currently locked and the handle removed so you can't open it.