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I have an ASHP for heating and hot water. Unless I use the “luxury” DHW setting, my shower mixer adds too much cold water as it requires the thermostatic valve temperature differential to be 12 deg C. Does any one know of a shower mixer that will work with a heat pump hot water cylinder feed, i.e with DHW between say 40 to 45 deg C, rather than at above 50 deg C?

Question Do you use less gas heating cylinder to produce DHW or direct from a combi gas boiler? My thoughts are - A combi will start up quite a few times and have a short run times, worst efficiency. Filling a cylinder will be longer run time, so should be more efficient. But I am not sure, what are your thoughts?

Hi All, The plumbers put in our UVC cylinder yesterday. I have raised a few things I spotted with the main contractor and he was getting in contact with the plumber. Could those of you with more experienced eyes please have a glance at my picture and let me know anything else that needs to be rectified. What I've noticed/questioned. 1. There is no tundish fitted and the over temp valve discharges via some 16mm pipework over a long distance to a hidden pipe into the main waste water system. 2. Does the tank require an overpressure valve on the cold feed? There is one on the cold main entering the house. 3. Does the tank require a thermostatic mixing valve? 4. Is it safe to have a switchable valve on the expansion vessel? Thanks in advance.

Hello, I am in the process of replacing the LPG tank in my property with an ASHP (Mitsubishi Ecodan 14kW). I currently have 2 solar thermal panels which cover all hot water demand for 5-6 months in a year (and I'm planning to keep them). It has been really difficult for me to find a suitable DHW cylinder that (in my limited understanding) would work well with ASHPs and solar thermal panels. Even harder to find options where I'd be able to monitor water temperature at different heights. Ah - the cylinder volume should be 250 litres. I really like the idea of Mixergy tanks because of volumetric heating, the plate heat exchanger (more efficient), the diffusers (for better stratification) and all the data I can get from the tank. However, they are very expensive and, for the ASHP+solar thermal versions, I cannot do volumetric heating (I've been told so by Mixergy). More annoyingly, it seems there is no dedicated solar volume, so it'd be hard to make the most of the already installed solar thermal panels if I want hot water in the morning. The pre-plumbed Mitsubishi cylinder ticked a lot of boxes, but it has 3 pumps and my installer warned me of audible noise (the cylinder is to be installed in a bedroom cupboard). It's also very expensive. I looked at options from Gledhill, Joule, Kingspan, Heatrae Sadia, ... and neither of them looked perfect. Yes, I am likely overthinking here, but would anyone have any advice or experience they could share with me? I haven't ruled out any options yet. Thanks a lot!

Hi all, I am currently in the middle of a new build (roof is now on). I need to start making decisions on heating/plumbing and I wanted to get some advice before proceeding. My idea is to use off-peak power supplemented with a solar array to run 2x Sunamps for DHW and UFH. The house will have a wood-burning stove, so although I will install UHF plumbing during construction, I might not utilize unless we feel we need it. quick info: - 2 bedroom Bungalow 120m2, well insulated (200mm EWI), triple-glazed, good air-tightness. - I plan to use Sunamp UniQ9 HW+iPV for DHW and another for UHF (UHF will be in two bathrooms and kitchen approx 40m2) - 2.3kw solar array (flat roof mounted) - wood burning stove 5-8kw Some questions I have so far: For DHW, am I right in thinking I need a unvented pressurised system for this set-up... as a pump is needed to draw water through the Sunamp? Is there any need for an expensive solar PV diverter? Surely I can just have a switch with a timer for sunrise/sunset after the inverter? Thanks everyone!! --

Excerpt from a previous thread. A member asked..... I am looking at an HTG thermal store for a DHW & Heating upgrade, I will be using a gas boiler heating the TS only, together with PV and immersion heater. The TS comes with a solar thermal coil fitted as standard. The gas boiler would normally be connected directly to the TS but I was wondering if I could use this solar coil for the system boiler to obtain some fluid separation ? The size of our home with # of radiators/bathrooms etc. would suggest I need a TS of around 300 litres but if I view the store as a battery should I install a larger store say 400 / 500 ltrs to help with the gaps in PV availability ? I guess there is a risk of oversizing as the volume should be within the capabilities of the immersion / gas boiler to recharge it ~ any thoughts or advice would be welcome. The TS is presently required for 12 radiators, 2 bathrooms & DHW, I am hoping to take advantage of my PV power hence the TS otherwise a fair size combo probably would have been the way to go. I am also building extra ground floor space so I also have been considering UFH but from your previous advice I am going to need more insulation to even consider going down this road. I have a beam & block floor with only 40mm poly then wyroc so not good, I am able to put 75mm underneath the floor between the beams which would help ~ but still not sufficient although if I am using this space underneath the ground floor as a store should I be too concerned. I have had experience with TS excessive heat in a flat some years ago, it was located in the centre of the flat off the hallway and I did ask engineers how to reduce the heat output but they looked blank at me. The small gas boiler was set at max heat output for efficiency as per the operating instructions but after not getting any useful help from heating guys, I had to turn the boiler down to half heat which totally made our lives much better, so JSH I appreciate this problem..... I presently have a traditional copper tank upstairs about 110 ltrs and is generally heated by the PV system and overall meets our requirements as there is only two of us. I am considering putting the TS in the utility room and using the heat to make a drying room etc. The TS is stainless steel and comes pre plumbed with a high efficient external heat exchanger (46lts per min, we have high water pressure) I could also add to this TS a similar external heat exchanger for UFH so it would give me scope for going the UFH direction. The additional copper header tank can be installed above the TS , is there any requirement for this to be higher than the radiators in the bedrooms or will it be ok ?