JohnMo

I do that as well, found in the shoulder months on a sunny day, all the heating was done via PV at a warmer day temperature. It would be zero at night and heat pump stayed off. Not sure how you square that with potential export. If I get export accepted, I will import at 12.65p, and export at 15p. So it may be more beneficial to run ASHP in the day, better CoP and no defrosting.

It's simple, you need to install a stove that takes primarily and secondary air from outside. There are many models to choose from, but it's important it takes all air from outside. Do not install a stove that takes room air. If you do you need to install an air brick which is bonkers in an airtight house. Do it correctly or don't bother would be my advice. If you haven't planned to put in an air inlet pipe, it's time to start.

Same area as me, some others on here also. Welcome.

Most possibly never did the a science subject. But doesn't mean you have to take things down to a level, to fit the lowest common denominator.

What does Even mean, except I just woke up, only time I ever heard it mentioned. Must live a sheltered life. I'm a fan of Grand Designs, could do with more technical details, but is only a hour program with adverts.

I was thinking of doing the same if I get export approved. Makes it fit and forget.

And change terminals and possibly the manifolds, and the MVHR unit. So that's easy. All to get 3kW cooling. Then in winter the unit will not turn down enough, so you spend all winter over ventilating. May as well just do A2A

Have now applied. They are after some strange paperwork, will see what comes back and what other bits are needed.

If you have thermostats in every room you really need a buffer. This is required to give somewhere to flow too for the heat pump. You really need to decide the following - suspect the installer and designer are all in arse cover mode. So wait about for the designer and installers to go round in circles and achieve nothing. Or bite the bullet, change it yourself or via a different plumber. 1. You may as well keep the volumiser, but have only attached between the 3 port diverter and the UFH. Or you could just remove it. 2. Remove all the actuators on the UFH manifold, keep wiring centre you have as it's makes an easy room reference place for actual room temps. But set at least one thermostat to full temp so there is always a call for heat 3. Set up weather compensation curve. 4. Open all loop flow regulators fully. Balance flows to UFH loops. If any room is too cold WC is set too low, reduced flow to room that are too hot. If all rooms are too hot reduce WC curve. 5. Over time balance the extreme cold end of curve. Set WC curve Start at 20 Outside at min flow temp allowed in heating by ASHP. Cold outside end set per the heat calculation provided by the installer, example -3 and 32 deg flow temp.

Why both? So now you have two units to pump out. Would you not just by-pass the septic tank?

I don't

Going to Costco does, wife wanted some more dishcloths, managed to spend £300, on what not much idea.

Not sure what your missing, just searched for instructions and it tells you everything you need to do Manual_VORTEX_S_H_Installation_v5.pdf

What's you heating requirements in kW at -3? If no heating system why not modern storage heaters, this would allow you to run on off peak electricity, to massively reduce running costs. Also if you PV, charge the storage heater with excess PV to make running the heating in shoulder months free or almost.

We had 30 degs yesterday - cool by England standards, but we still pulled 50+kWh of heat out the house by UFH run in cooling mode. Including heating DHW, used all of 11kWh of electric, all provided by the sun FoC via solar PV.