Posted by: @webcmg

Does anyone happen to know the current month energy consumption update interval for the 700/6 controller?  It certainly isn't realtime (no idea why not!) and I have a significant variation in usage at the meter vs usage at the controller. If I can figure out when the controller updates I can rule out something else using so much energy.

Thanks,
Chris

Hi,

Check to see if you have a booster heater (immersion) or backup heater that may be operating.

@Derek-m @kev-m @alec-morrow @mike-patrick @mattengineer

General update. Vaillant attended and resetup the controller and checked the glycol levels. They set the programmer to 0.7 heat curve and 21 deg desired heat temperature. Room stats in hall and landing set to 18 deg c, others set to 21 (kitchen/snug area), lounge and dining room currently set to frost protection. At night the thermostats are set to three degrees below day time temperature as advise by the engineer. Hot water set to 50 deg c and recharges if it drops by 5 deg between 05:00 and 21:00.

I've been monitoring temps and, sadly, it's the same story.  Warm downstairs, cold upstairs with room temps (now measured by my array of disconnected tado wireless trvs repurposed from my old house) between 14 and 18 deg c (see image). The landing stat does not turn off unless sun is shining directly through the window for an hour or so in the middle of the day and the temp, on the landing only, reaches 20 deg, other rooms remain at or, below 18 deg c. Rooms with vaulted ceilings and lots of windows (Bed 1 and 4) tend to be the coldest, ensuites are also very cold - not ideal at all.

24 hour Kwh at the meter is as follows, I think the latest is still reletively high:

16/01/2022 - 56.2 kwh

17/01/2022 - 48.7 kwh

18/01/2022 - 67.1 kwh

The installation plumber attended and measured the flow and return temperatures on each of the radiators. They were all within 2-3 deg c with flow ranging between 35-37 and return 32-35 deg c. He is happy that the plumbing is working as intended. Flow rates on UFH pumps have been decreased. Flow rate of radiator pump set to its highest setting. Flow rate indicators typically @ 2.5 litres per minute.

To experiment and optimise, what steps would you take now to try to increase heat whilst maintaining some level of economy? Should I:

• Leave on 24/7 at 18-20 deg across the whole house?
• Increase the night time temperature?
• Increase the desired temperature from 21 deg c on the VRC700?
• Increase the heat curve?

~£12 per day seems expesive given upstairs isn't warm 🙁

Thanks in advance for any further advice.

Posted by: @derek-m

Posted by: @webcmg

Does anyone happen to know the current month energy consumption update interval for the 700/6 controller?  It certainly isn't realtime (no idea why not!) and I have a significant variation in usage at the meter vs usage at the controller. If I can figure out when the controller updates I can rule out something else using so much energy.

Thanks,
Chris

Hi,

Check to see if you have a booster heater (immersion) or backup heater that may be operating.

Immersion is off at the switch - how might I identify a backup heater? I think the difference in values is probably just a timing issue.

@webcmg 

Just for some comparison, our house is a similar size with an Arotherm Plus 12kw, Unistor and VRC 720. We're just relying on the outdoor temp sensor with the curve set to 0.4.  We just have the UFH and radiators stats set to max and on all the time and we're averaging 30kw per day for the past week. Our flow temps vary between 30-35 depending on how cold it is outside.

We've adjusted the heat curve over time and 0.35 - 0.4 seems to suit our home best. Hope you get to the bottom of your issue soon.

@webcmg is you need a higher curve for radiators than the floor…but more heat means more energy consumed.

and the floor temps need to be mixed down by a mixer controlled by the vr71 which works with the vrc700 

You can’t get any manageable out come with out installing as vaillant design engineers (in Germany) intend

Posted by: @colin

@webcmg 

Just for some comparison, our house is a similar size with an Arotherm Plus 12kw, Unistor and VRC 720. We're just relying on the outdoor temp sensor with the curve set to 0.4.  We just have the UFH and radiators stats set to max and on all the time and we're averaging 30kw per day for the past week .

We've adjusted the heat curve over time and 0.35 - 0.4 seems to suit our home best. Hope you get to the bottom of your issue soon.

 

 

Wow, this sounds incredible. When you say max assume you mean any TRVs and thermostats at say 25 deg c or something? What is your desired temp set at on the vrc700? 

Posted by: @alec-morrow

@webcmg is you need a higher curve for radiators than the floor…but more heat means more energy consumed.

 

and the floor temps need to be mixed down by a mixer controlled by the vr71 which works with the vrc700 

 

You can’t get any manageable out come with out installing as vaillant design engineers (in Germany) intend

And I found out that it was Vaillant themselves who 'outsourced' the system design... sigh.

@colin assume your setup has a controlled mixer?

Are you using vaillant mixers for the floor? Or is there a pump for each floor zone?

raise heat curve and shut down all the floor and see how the rads respond?

Posted by: @webcmg

Posted by: @colin

@webcmg 

Just for some comparison, our house is a similar size with an Arotherm Plus 12kw, Unistor and VRC 720. We're just relying on the outdoor temp sensor with the curve set to 0.4.  We just have the UFH and radiators stats set to max and on all the time and we're averaging 30kw per day for the past week .

We've adjusted the heat curve over time and 0.35 - 0.4 seems to suit our home best. Hope you get to the bottom of your issue soon.

 

 

Wow, this sounds incredible. When you say max assume you mean any TRVs and thermostats at say 25 deg c or something? What is your desired temp set at on the vrc700? 

Pretty much. I have the radiator TRVs mostly up to max, and the UFH zones mostly set to 25 deg, then let the heat curve adjust the flow temp. I use the TRV to limit the temp in the kids rooms. The key is to get the flow temp as low as possible while keeping the house at a comfortable temp. Our indoor temps are around 22-24 degrees, based in a relatively cold/exposed part of Scotland, but it's a well insulated new build.

Posted by: @webcmg

 @colin assume your setup has a controlled mixer?

That, I'm not sure I can answer. We have a Snug Underfloor Heating solution, which has manifold, actuators etc and it looks like it mixes but still trying to figure that part out. The heating engineer is due back soon to install the Internet Gateway and cooling resistor option so hopefully I'll get a better hand-over than I've had.

Posted by: @colin

Posted by: @webcmg

Posted by: @colin

@webcmg 

Just for some comparison, our house is a similar size with an Arotherm Plus 12kw, Unistor and VRC 720. We're just relying on the outdoor temp sensor with the curve set to 0.4.  We just have the UFH and radiators stats set to max and on all the time and we're averaging 30kw per day for the past week .

We've adjusted the heat curve over time and 0.35 - 0.4 seems to suit our home best. Hope you get to the bottom of your issue soon.

 

 

Wow, this sounds incredible. When you say max assume you mean any TRVs and thermostats at say 25 deg c or something? What is your desired temp set at on the vrc700? 

Pretty much. I have the radiator TRVs mostly up to max, and the UFH zones mostly set to 25 deg, then let the heat curve adjust the flow temp. I use the TRV to limit the temp in the kids rooms. The key is to get the flow temp as low as possible while keeping the house at a comfortable temp. Our indoor temps are around 22-24 degrees, based in a relatively cold/exposed part of Scotland, but it's a well insulated new build.

Thanks going to give this a try...

@webcmg Good luck! Bear in mind it'll take a while heat up the screed etc. I've got the Room temp Mod set to inactive so it solely relies on outdoor temp/Weather Comp.