Hi

My in-laws have a mix of heating systems:

- Oil fired boiler - they are thinking of switching to air source heat pump in the near future
- Downstairs wet UFH in nice thick conc slab with wood flooring throughout. Upnor manifold, stats in each room & Upnor programmer.
- Bedroom wet rads with manual TRV and mech stat on landing. The mech stat is influenced by the hall UFH heating the stairwell. Rads have their own programmer.
- Electric UFH in bathroom and ensuite. Use individual heatmat programmer
- Hot water cylinder. Uses the rad programmer

They want one box that sorts out all of the above instead of the separate units.

Most of the time the house in balanced through trial and error but overshoot is an issue upstairs at night. I think this is due to heat coming up from the ground floor.

The landing stat isn't particularly useful, they tend to manually turn it up and down to trigger the rads circuit on or off. To be honest 9 months a year the rads aren't doing much work because the downstairs UFH keeps the house cosy. They'll nudge the stat up on a cold evening to warm the bedrooms and that's when the overshoot happens, so they end up calling for more heat and opening windows on the coldest nights.

I'm thinking along the lines of:

- Electric TRV in bedrooms to get rid of the landing stat problem.
- Predictive/compensating controls to avoid the overshoot caused by the UFH/rad interaction.
- It'd be nice to get the bathroom/en suite electric UFH on the same controller but to be honest they don't cause an issue and just sit in the background.
- Work well with current oil boiler (high peaky output) and future air source (low steady output)
- Online access - they go away a lot and then come back to cold house in winter with UFH that takes 12 hours to heat up so need to switch this on in advance. They're nearly 80 so do get very cold when the house is cold.