Main website

http://www.passivuk.com/

Thanks @tim441. Interesting timing, as Passiv are a currently an advertising partner on Renewable Heating Hub, so I think I'll partially hijack your thread and transform it into a "Passiv Smart Thermostat – Help & Forum Support" where people can ask questions and I can get the team at Passiv to answer questions anyone has about their products and how they're complimentary to heat pump systems.

How do people like this? I was looking for thermostats that are for ASHP that do not have an ongoing subscription fee 

I also want to know if this can be used with a Grant R290, and if so, do I need the Aerona Smart Controller or could this replace it entirely? 

@petch I’ve not come across anyone yet that’s used these thermostats so can’t comment on that, but @fraser-allison or @will-h might be able to comment on compatibility with your Grant heat pump.

@petch We are not yet compatible with the R290 from Grant but we do support their R32 units. 

You can find all the models we are compatible with here.

We regularly add new integrations, so hopefully we will support the Grant R290 in the not too distant future!

And you are correct that we don't charge any subscription fees - all the features of the Passiv Smart Thermostat (flow temperature, time of use tariff and solar PV optimisation) are included for free!

We are still working on the Grant R290 - but since my last post we have added support for AUX and Haier heat pumps!

@will-h 

I wasn't intending to connect the DHW cylinder immersion heater to the Haier heatpump which I'm installing, as I'd like to keep it seperate in case of HP failure and also save installing another cable run. The Heatpump will be doing heating and DHW to 51°, which is the temperature which the immersion is set to at present and this is currently switched by an economy 7 timer box.

However I've read that "The (Passive) system will still try, once per week, to run an antilegionella cycle though for safety purposes and currently cannot be turned off"

Will the passiv controller still be able to control DHW schedules without throwing a fault when it doesn't see the expected legionnela cycle temperature being met?

Hi @singlespeed 

That's fine we have installs where the immersion has not been connected for exactly the use case you describe. The Passiv Smart Thermostat will control your hot water just fine and will not throw up any errors. 

The Passiv Smart Thermostat will still try and do a legionella cycle. It always try's to do this in the most efficient and cost-effective way, which means running the heat pump first and then using the immersion to get the temperature above 60c (if required). Obviously it will be unable to control the immersion, but because the Haier is a high-temperature R290, it will probably manage to do a legionella cycle successfully just using the heat pump!

Is there any expected time frame for an update to be able to switch off the legionnela cycle?

I get the point of the high temperature killing the bacteria. But removing one danger and increasing the risk of scalding injury, without any way to disable it, is making me question wether to bother fitting the Passiv controller.

I'm sure I'm not alone where we have a high daily turnover of the cylinder volume and store water at a temperature where the risk of bacteria growth is less likely.

@singlespeed No timeframe at the moment. However we can remotely disable it for you as long as the system is internet connected. You'd just need to get in touch with us (or you can message me on here) when it is installed.

Thanks Will.

I'll probably be a week or so before getting power on.