@transparent I was offered a Vaillant HP (amongst several others) the size / range appropriate for my situation didn’t even make it to the short list as the gas used in them requires quite a lot of air around the installation site that we do not have due to windows and doors. So Vaillant were off the possibles list.Regards, Toodles.

@mark3robinson just to ease you pain a little bit, in general direct support from manufactures to the customer is not really a thing, vaillant, mitsubishi and others do the same, they deal with their partners rather than the customers. So regardless of what brand you choose, the installer is the key element.

Evening! About to have an ASHP and new rads installed, delighted to find this forum!

Welcome @marknw - For you and @mark3robinson who has also just joined here, could you please do us a favour...

... tell all your friends and relatives to visit here before they decide to install heat-pump, solar panels, storage batteries or whatever other technology they fancy! 🤨 

@transparent There is a very friendly group of knowledgable people contributing and there are also others like myself who are to a great degree, self-taught thanks to many others on the internet and from experience gained through embarking on various renewable energy projects. I have certainly benefited fom others experience on this forum (thanks all of you!). By the time I had any technology installed, I knew what I wanted and this meant choosing installers who were prepared to do what I wanted rather than a ‘bog standard’ install that they wanted to fit! Regards, Toodles.

@iancalderbank good to meet you! Sadly my solar system died today, one of the tubes exploded on the roof causing a loss of water pressure so decommissioning begins! RIP solar! 😀

Posted by: @technogeek

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the previous owners had an evacuated solar tube hot water system fitted which after me personally servicing it got it back to running during the summer.

Posted by: @technogeek

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one of the tubes exploded on the roof causing a loss of water pressure

Sorry to hear this @technogeek

But I'm puzzled by your description of the failure.
I too have a thermal solar system. As I installed it myself, I have a pretty good knowledge of how the component parts fit together.

Damage to one or more of the evacuated tubes should have no effect on the circulation water.
The water/glycol mix passes through a copper manifold.
The 'hot end' of each vacuum tube slots into a pocket on that manifold.

There is no connection between the circulating water and the vacuum tubes themselves.
I can remove tubes for cleaning and re-insert them into the manifold without draining the system.
To maintain thermal conductivity, I apply more heat-transfer compound to the end of the copper collection-rod before re-installing.

If you had a loss of pressure, from where did the fluid leak?

Photo?

@transparent I went on the roof tonight to clear all the glass up. I think due to the manifold's age (25+ years), it has developed a leak filling the tube with water hence it exploded with the steam pressure. I pulled out the copper tongue briefly from the manifold and water / glycol rushed out which as we know it should not. It would require a new manifold and tubes which is not worth the hassle as it only produces 4 to 5 months of the year. Will decommission and look to replace with PV's, at least they produce something all year round plus they will be more versatile with no servicing as I have enough to maintain in my house! Lol

I understand @technogeek

However, as this is the main Welcome Topic which everyone reads, I need to pick up two assertions you've just made.

1: A Solar-thermal panel is able to produce usable output in winter.
It works from solar radiation, with very little loss of effectiveness in lower air-temperatures.
A clear/sunny day in December/January will still yield water in excess of 60°C

2: A PV solar-panel which is made from silicon has a maximum theoretical efficiency of 23%.
That's due to the way in which a photon (light particle) frees an electron from the outer shell.
In practice PV panels available now (summer'23) have max efficiency of about 19%, which is pretty close to optimal!

However, a solar-thermal panel operates at around 80% efficiency.
You would need to have PV panels covering four-times the area of a solar-thermal panel in order to heat the same quantity of water using their electricity.

That's why solar-thermal remains popular.
It's a more efficient use of roof area.

The energy output (in Joules) of the Solar-Thermal identified on the right
is equivalent to the energy produced by the six PV solar panels beside it on the lower roof.

@transparent I’v read that solar thermal will work mounted vertically on a wall though I didn’t see any mention of efficiency for such arrangements. In terms of PV panels; my 21 panels have a combined theoretical rating of 8.1 kWp. and some are on roofs at various orientations in the region of SSE to SSW and ten panels are garden mounted at approx SSE, The maximum combined output I have noted is approx. 7.2 kWp; the more general performance is in the 5-6 kW region however.Regards, Toodles.

Hi All!

Glad to have stumbled across this forum. Recently moved into what will (hopefully) be a forever home. As you do, the more you look the more you find 'odd' bits around the house. Has a small (garaged size) granny annex (we're thinking future home office...), but on its own gas supply with combi boiler (despite being all of 3 m detached from the house!). So in the lucky position of 2x gas boilers easily requiring replacement in next 5 - 10 years...

Started out with an Octopus survey to gauge if ASHP possible without gutting the current heating setup, (very thankful previous owners put in what feel like large rads compared to our last home), which seemed to say yes for the main house (but calcs stated 50C flow temp). Credit where credit's due they don't seem to have minded the mountain of questions I've asked but I'm resigned to finding out my install doesn't fit their 'standard' service offering.

Currently hoping to find sufficient advice/guidance to see if I can justify a switch to ASHP, Solar PV and Batteries (to both myself and the boss!) that will do everything in a single system.

Challenge seems to be, how to know if you've truly found competent installer! Seems sufficient evidence ASHPs (the units themselves) work, just a case of whether your system is designed and commissioned correctly...

Meantime I'm going to continue trying to digest all the info I can get my hands on and might have a crack at filling out my own heat loss calculations. Wish me luck!

Cheers Declan 

@declan90, welcome to the forums. Big journey ahead – keep us updated with your progress and feel free to start a thread dedicated to your project where you can discuss your heat pump, PV and battery decisions.