ProDave

He says he topped up the glycol levels so that makes sense.

Yes that is the tundish. It should remain bone dry. IF any water passes through it would pass on the inside, it is just there so you can see if anything is passing through. You could try rolling up a bit of tissue or toilet paper and sliding it into the space inside. That will show you if there is any discharge even when you are not watching it. It that remains dry over a few days as you use hot water and it gets re heated, then there is nothing wrong with the white expansion vessels.

"servicing a heat pump" might be slightly specialised, but just about any plumber should be able to do all the normal things related to the rest of the system like expansion vessels pressure checks etc. Those would all be the same if you had a gas or oil boiler as the heat source. So it looks like the red heating expansion vessel is okay. Just the 2 white ones to check. Can we have a photo of the pipework under the tanks? We are looking for a Tundish that will look a bit like this When you find something like that, have a close look at it. If there is a problem with the 2 white tanks that the plumber wants to change, then whenever it heats the hot water, you will see water dribbling down the inside of this. It should be bone dry normally.

I had similar with the flashing for my stove flue that bent up one corner in a storm. My repair was to bond it down with appropriate goop. Has not happened again.

Why not dig up the flower bed, install a proper soakaway under the flower bed then put the soil and plants back?

Just see how it goes for now. Check next time the heating is off and all cold (first thing in the morning?) and see if the pressure has stayed up or gone back down again.

That's why I am suggesting @canalsiderenovation does some investigating of her own with our guidance.

Quite apart from the issue of the gap may not have been pulled tight all the way, to me it looks like the joining strip may have been cut too short and it seems to end above the bottom of the window. That might explain the daylight you can see?

Oh you have 3 in total. The red one will be for heating, that is your one with the immediate issue. The TWO white ones are for the hot water. There is no indication that there is actually an issue with those yet. The fact this guy suggests replacing the 2 white ones but has not addressed the low pressure on the red one has done nothing to give me confidence in him. Lets tackle each separately. The white ones don't have a pressure gauge, they will be at mains water pressure. They are to take up the expansion when the water in the tanks gets heated. IF they have a problem, you will see water being discharged via the tundish after you have say had a shower and used up some hot water and the cold water that has entered the tank to replace it is being heated. If you want help identifying what the tundish is, post a picture of the pipework below those tanks. A further note, those tanks are of the type where you can take that bottom flange off and use that access to replace the bladder if it has burst. But I suspect the labour charge would make that more expensive than just replacing it, if they are faulty. Summary. If you just accept that quote, you will get 2 shiny new white tanks that may or may not be faulty, and the low pressure on the red one will still be the same.

They should not fail that regularly. Do you want to do a few checks with us to really determine has it failed, or does it just need the air pumping up? If they do fail regularly it might be a sign they are too small. What size are the ones there? We have only seen one of them so far where is the other one?

https://www.screwfix.com/p/flomasta-potable-expansion-vessel-24ltr/131kk £40 each from Screweys, so that makes it £310.40 for labour (including the VAT) How long did they say they would take and how many people?

When booking the next person, say you want a "G3 service" If they mumble, pause, or say "what" they are not the right person. Before that, when the system is next cold and reading 0, you could try reading the pressure at the valve on the top with a car tyre pressure gauge and tell us what reading you get. It might just need topping up.

Distance from the coast. I found that in Oxfordshire, in winter like this last week, it can get very cold, Benson was -8 earlier in the week. And in a summer heat wave it can be one of the hottest places without the coastal influence to moderate things. That "inland" effect is very evident in the mid west USA. for my sins I had 4 weeks just outside Chicago in summer, and found it unbearably hot, you really wanted to be in an air conditioned building or car to be comfortable. Then i went again for 2 weeks in December and found it unbearably cold. When I mentioned the cold a local said something like "cold, this isn't cold, you wait until it gets below 0" (he was talking Fahrenheit) I did wonder how much spring and autumn fall they had where the temperature was pleasant. I suspect not much.

Okay keep the container as a store cunningly hidden by the new workshop built in front of it.

Drag the container to somewhere it will be accessible, then build the new workshop. Might annoy the neighbours a bit until the container has finally gone.

If you are happy with the container, clad it with nice wood cladding, put a window in one side and tell here the new workshop is finished. If you really want a new workshop, it is obvious, the new workshop is NOT built where the container is, so the container can remain until the new workshop is complete and everything moved, only then can the container go. This is the very reason we got the static caravan included with our planning with permission to retain it. It does look better than a shipping container.

Yes, already proven here. Very early on in the build I confirmed the heat loss calculation was correct by leaving a single electric convector heater of known power on and plotting internal vs external temperature for several days. That gave me the Dt for a given power input, which tied exactly with the calculations. In any event I bought a 5kW ASHP to satisfy a max demand of just over 2kW. For me the only leap of faith was no heating in the bedrooms. SWMBO likes a cool bedroom about 18 degrees. Usually we have to keep the bedroom door shut to keep it down to that. In this cold spell we had to open the bedroom door occasionally to let a little bit of heat in, and still achieved the required temperature with no actual heating there.

Get all the kick boards off and go around the whole room perimiter with a can of spray foam and fill the gap between the walls and floor especially where the drain pipe goes down. It sounds like there is insulation under the floor boarding, but the (sadly usual) lack of attention means there are likely to be cold draughts getting in from almost anywhere between the wall to floor junction.

Only a mere -8 here last night and not been above 0 for several days. Snow well over 12" drifted deeper in places. I shovelled the snow off the balcony today as I was getting concerned at the weight. Still able to get in and out. The gritter made an appearance today followed not long after by the postman, but yesterday's bin collection did not happen. Local mountain pass shut and A9 north of Helmsdale shut then open then shut...... Still toasty warm inside. But this is "normal" winter weather here so no surprises been here before. A power cut now would not be fun, I would be back and forth to the wood shed frequently if that happened. No sign of an end to the cold snap for another week here. As to be expected, I have not seen the ASHP need to defrost while it stays below 0. RH inside house starting to drop, about 32% now.

So the ASHP is consuming 1.6kW to heat the house, assuming a COP of 3, that will translate to 4.8kW of heat delivered to the house. It is very cold at the moment. Our very well insulated 150 square metre house needs about 1.5kW of heat at the present sub zero average outside temperature. So your house is larger, older and no doubt less well insulated, so 4.8kW of heat does not seem at all unreasonable. Don't expect to reduce that significantly other than as above move to a smaller much better insulated house. What exactly does that mean? surely not the heat pump is set to heat water to 88 degrees? Sounds very like it does not have the right sort of hot water tank for a heat pump. Not much you cn do there as the system is not your to make alterations to. It sounds like your expectations of the property are not matching reality, and as above again, all you can do is move to a better property.

If you still have the old type of ball cock valve that shuts off the water slowly and can take ages dribbling to fill the last little bit before shutting it off, then change if for a modern fill valve, that will fill at full flow until quickly shutting off when full. You will never again want to go back to the old slow ballcocks.

So that is not a rainwater pipe, but outflow from a bathroom? Bodgit and scarper plumbers strike again. Replace that downpipe with the proper round downpipe that will mate with the other black pipes all the way down.

Cuddle Puddle

They may be a reputable company for complete light fittings, but I have not found spares on sale anywhere yet. Perhaps try contacting Siteco directly and asking them if they can supply you with a new driver?

Most likely to be the driver. Trouble is I can't find that exact driver anywhere. The important thing is you want a constant current driver set at 145mA or an adjustable one that can be set to that. Most I have found are 300mA or more. Then it has to be small enough to fit in the space occupied by that one. If it were mine, I would open up the case of that driver which may involve cutting it open of the plastic is welded or glued shut. Like @Temp my money is on a failed capacitor or 2 which is probably repairable. Even if you then had to glue the case of the driver back together. P.S the U Out 340V DC makes one not trust much of what is written on it.