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Plenty of information on ASHP is available on this site and very little on hybrid heating systems, i.e. boiler and ASHP. A few manufacturer designed hybrid systems are also available. When we built our house it was with an Atag gas combi boiler. We then installed an ASHP mostly for cooling, but it also heated our house well last winter and provided hot water via an UVC. The system below could easily be replicated by anyone wanting to install a hybrid heating system meaning little or no changes to heating system such as radiators. So the Atag boiler only 2 years old has sat idle for the last year. For periods where the CoP of the heat pump, means gas is cheaper why not marry the boiler and heat pump together. Most of the off shelf solutions, rely on the gas boiler doing the hot water, not what I wanted. Most the time the ASHP is way cheaper than gas (especially with solar). So makes sense to do hot water via the ASHP most of the time. Most ASHP already have all the control logic for hybrid mode built-in - mine does. I have a few location issues which makes the implementation a little more complex than I could be. Boiler and UVC are about 20m plus away from the ASHP, with UFH in the middle. The solution I chose to use has the boiler on a separate circuit to the ASHP. Combi DHW tails are not connected to anything and the isolation valves closed. Phase one Get hybrid hot water heating. Had a 40 plate PHE sitting doing nothing, so inserted in the flow line from the ASHP close to the UVC, the other side to combi boiler heating circuit. Set max flow temp to 60 on the gas boiler. I can change the rate at which the boiler adds heat (gradient), set to a max of 2 degs every minute. Initial run was all manually done to check concept. With ASHP only the reheat time of the UVC is around 40 to 45 mins, with boiler engaged about 20 to 25 mins. During test, I monitoring the ASHP and gas boiler and both work well together, neither running away temperature wise. Now how to automate. All control logic is in the ASHP, to use a boiler as a secondary heat source, you can set different outside temperatures for the following control schemes - 1. ASHP only, 2. ASHP leading, boiler following, 3. boiler leading ASHP following 4. boiler only. ASHP controller supplies 230v as a control signal to the boiler. But boiler is 20m plus away from the ASHP. So used a Shelly relay at the ASHP end and a remotely controlled Shelly relay at the boiler end. Set up a scene in the shelly app, switched live to ASHP end Shelly energised the boiler end Shelly relay. All worked fine. Set the hybrid mode (ASHP leading) to start at 7 degs and a delayed start of 10 minutes for the boiler, after cylinder heating starts with the ASHP. PHE, boiler on left side ASHP on the right. Phase 2 UFH - coming next.

Hello all, New here, so be gentle! 🙂 I'm trying to set up for an EnerPHit project on our house here and am really struggling with the windows. Having found this site through searching for this type of issue I found a fantastic chart by @Visti to compare the prices vs Uw values for a multitude of suppliers. It's really interesting to see, however as it's now nearly 5 years old I wondered if anyone has created an updated version at all? After many months of wrestling I have a quote for some Rationel windows and it's alarming to say the least and I can't think that it's simply gone up by that much in 4-5 years. I have had a scout through more recent posts, but could find anything.

Still trying to chose CH and DHW within all the constraints of my conversion and conservation area. Builder is recommending I have wet UFH to future proof. Has anyone got any experience of the Sime Murrelle Revolution 30 gas (it would have to be LP) and a small heat pump (which confusingly doesn't need to have an external box) so is recommended by the energy saving trust. I'm doing this to get through BC now with adequate heat. I want to have future options so think I need a thermal store to allow for possible solar thermal, may be woodburner and back boiler, GSHP if they become cheaper, or compost heat is I become a hippy. Does such a thing exist? `I've read you have to spec in advance. Am I correct?

Or perhaps I should have written: Choosing the correct one isn't easy I need to embed threaded bar in non-cracked concrete. That's why SEs and others say 'You need a chemical anchor'. Have you looked at the range of them on offer? Which does what for whom under what circumstances isn't made clear at all. So it's off on yet another electromagnetic adventure: and apart from suppliers websites (which I automatically distrust) there's precious little to engage an interested but skeptical customer. True enough, I did find this . But the authorship of the site isn't made clear and there's a lengthy disclaimer. (at the bottom of the page). I trust that just about as much as I trust Donald. Screwy's , TS, and local BM sites and others aren't interested in anything other than sales. Fischer do a technical support site (just a phone number), but they only focus on .... you guessed it. Why does styrene matter (as in styrene-free) ? Is generic stuff just as good as branded ? Who or what is Vinylester? (yes it's is a resin produced by the esterification of an epoxy resin with an unsaturated monocarboxylic acid. but what the Hell is that? What's the difference between high performance and normal stuff? Why is there such a price range? Cheap = bad, expensive = good ? What's good enough (for my job)? Does anyone know of a site which simplifies this mess of advertising claims erm, (sorry) , information ?