@derek-m I'm afraid I can't answer why that is, other than the builder who fitted the UFH/Raditors and all the plumbing was different from the company who did they ASHP.

@colin are you tempted to replace the glycol and see what difference it makes to the system performance and efficiency? Is there any data that indicates the potential differential in efficiency?

Posted by: @colin

@derek-m I'm afraid I can't answer why that is, other than the builder who fitted the UFH/Raditors and all the plumbing was different from the company who did they ASHP.

Hi Colin,

Are you certain that you actually have dump valves installed? If so, where will they actually dump the water and glycol mixture should they operate?

If my understanding is correct, having antifreeze included will not stop the dump valves from operating under the specified conditions.

Posted by: @webcmg

@colin are you tempted to replace the glycol and see what difference it makes to the system performance and efficiency? Is there any data that indicates the potential differential in efficiency?

It should be possible to roughly calculate the effect if you know the concentration of glycol.

Glycol has a lower specific heat capacity than water, so can transport a smaller quantity of heat energy than a similar volume of water. The greater the concentration of glycol, the lower the quantity of heat energy that will be transported.

Posted by: @derek-m

Posted by: @webcmg

@colin are you tempted to replace the glycol and see what difference it makes to the system performance and efficiency? Is there any data that indicates the potential differential in efficiency?

It should be possible to roughly calculate the effect if you know the concentration of glycol.

Glycol has a lower specific heat capacity than water, so can transport a smaller quantity of heat energy than a similar volume of water. The greater the concentration of glycol, the lower the quantity of heat energy that will be transported.

I haven't calculated it but I've read it's about a 5% loss for a typical ASHP treated with a glycol based inhibitor vs pure water. That will add up but won't make a noticeable difference to your COP. 

One point to note is that the specialist heat pump glycol solutions also have corrosion and biological inhibitors; they're not just anti-freeze.  Unless it's done on the cheap using car anti-freeze of course. But nobody would do that. Would they...?

Hi all, my smart meter connectivity issues now appear to have been resolved and I can see consumption at 30 minute intervals via the Bright app.  Does anyone know if it is possible to view this data in Home Assistant?  Many thanks.

@webcmg Hi webcmg, it is. Here's the integration I used. 

https://github.com/HandyHat/ha-hildebrandglow-dcc

@colin thank you!

@colin what card are you using to display the usage?

@webcmg Hi, I use the SMETS2 frient Electricity Meter Interface which uses Zigbee and quite easy to set up with ZHA.  

https://www.amazon.co.uk/20207000-Electricity-Consumption-Battery-Powered-SmartThings/dp/B08WXT6HHJ

I also managed to get my Geo Trio3 IHD plus wifi module working with HA but that was more challenging with having to edit YAML files and quite tricky.

Both give live meter readings so I can guess what the Heat Pump is up to.

@webcmg Hello. I know this is an old thread, but I have just had Vaillant ASHP fitted, and am working my way round how to get the best out of it. The fitters said 'Leave the controls alone!'. Which I have, of course, ignored totally!. I have messed up once or twice, but factory reset is always there as a fall back! Whatever you do, do not leave the hot water on all the time. I have set mine to run for a couple of hours - midnight till 2 am - Tues and Weds, plus Sat and Sun. Loads of hot water, much lower power consumption.

@yogabob this is still very much active thread as our developers continue to try to resolve the performance and efficiency issues. Our DHW heats up for an hour each night, it easily hits the 48 deg within the hour and averages between 2kwh and 3kwh per night at this time of year. Not sure I understand why you only heat it on two consecutive nights twice a week?