Frost Protection turning heating on full

andrewjleeson

Hello all,
I keep finding my heating is blazing during the night while frost protection is active due to the cold weather. I have to turn down the radiator temperature on the boiler to stop it heating the whole house during the night. My understanding was frost protection runs a low temperature throughout the system to keep it from freezing, not running at 18 degrees at 3am. Is there anything I can do to reduce the temperature frost protection is running the central heating at? Tado wireless thermo only, no radiator thermostats.

Thanks

Andy

Phillip_PAL

Surely Frost protection would be 5 degrees, doubt its that, it should gradually turn on low as it approaches your schedule setting.

Could it be early start with your next schedule set to reach 18?

If so when does it achieve 18 ?

if it is reaching 18 more than 20 mins early prior to your schedule regularly then ask for that TRV early start to be reconfigured as its over eager.

However if it's failing to achieve the set time regularly by more than 30 minutes due to poor performance of radiator or poor thermal losses of room (assuming you haven't left windows or doors open) then the system is just trying to do the unachievable in which case you should disable early start and configure schedule manually in steps for how soon you are prepared to heat.

andrewjleeson

Thanks so much for the input Phillip.

It's not early start as the heating is set to come on at 16 degrees at 5.30am. In the last cold snap I woke to a boiling house at 3am as it was trying to heat to 18. I assumed it was the frost protection as it's never done it before and coincided with the cold snap.

All very confusing. I turned down the rads on the boiler last night again as I know FP was due to kick in due to the cold weather.

Thanks again for your input, any other ideas?

Andy

Montage

What is your night setback temperature set to?

cbd20

@andrewjleeson I assume you're talking about the tado frost protection setting here and not any boiler frost stat.

Tado frost protection should mean the heating doesn't come on until the temperature in the room with the thermostat drops to 5 degrees. I highly doubt that's what's happening in your situation.

You're saying it's heating to 18 degrees, so just to clarify is that the temperature displaying in the app or does it still say frost protection in the app?

If it says 18 degrees, then that would imply tado has explicitly switched away from your frost protection setting to 18 degrees. The question then becomes "why has it switched?". If you go to the Room tile in the app, view the graph and long press on the graph, a little bubble will pop-up providing more info. Drag this back through the night to see at what point the heating suddenly changed from frost protection to 18 degrees. The time it happened might provide some clues. If you see a little hand symbol then tado believes the heating was "manually" changed. Note that any change away from the schedule is considered to be "manual control", so that includes any commands by a smart assistant.

Do you have any routines or anything running on an alexa/ Google home? Occasionally these commands are misinterpreted and can trigger tado devices...

andrewjleeson

Many thanks for all of the input.

My heating is off at night, we don't use it much, hence why it's so strange the heat kicks in during the cold periods.

I turned the rads down on the boiler last night, so will leav we as normal tonight and report back in the morning on the findings of the graph.

No routines on the Echo, it's purely via the app.

Thanks again for all of your input. Will report tomorrow

Andy

Montage

Posting up a screen grab of the heating schedule will help.

cbd20

@andrewjleeson it's worth noting that the inspection of the graph can be done for the day where you've already had the issue just by scrolling back to that day. No need to wait to see what happens tonight.

Phillip_PAL

Beware that early start can jump a time block.

Noticed this last night as very cold outside, hallway rad (which I have recently had early start reconfigured to start earlier as appropriate) - it turned on to hit 19 even though the next time block is 18. It was actually correct though, it hit 18 about 20 minutes before that schedule but reached 19 at about the right time which wouldn't have been achieved if it didn't have the head start.

Early start takes into account the colder outside temperature to determine the start point not just the actual temperature of the room.

You need to check the tile / further room details during the heating to see if early start is mentioned. I don't think you can see historically on the graph definitively that early start in effect as it just shows target temperature (but will have hand icon if manual as opposed to auto schedule).

I have tado hooked up to home assistant and I can see there the early start history and you can also create a graph representation of % heat request to better understand both Tado behaviour and also performance of room.

Recently had a new radiator installed to hall for better performance (previously it was just taking the chill off the room but never warm).

Ideally I hope to improve the slow heatup further by ensuring its properly balanced with rest if system along with slight improvements to insulation and drafts at cold spots where possible. It's nice and toasty at upstairs of hallway now, but only just ok at bottom of hallway and beginning to struggle in the cold weather.

I can then ask for early start to be reconfigured so it's not as aggressive if it reaches target too soon - I would prefer it to just miss rather than start heating full whack 30 minutes earlier for the non tado trv rads.