minimum open percentage

guardi

Hello,

The pin of some of my valves need to travel at least about 1 millimeter before water starts flowing. That means the knob needs to open at least 30-40% for a meaningful amount of water to flow.

Is there a minimum percentage setting in Tado knobs? In Honeywell Evohome there isn't, lots of users like me are having the issue where the knob opens a little, but the valve is essentially still closed, and water starts pushing through the bypass for a couple of hours until the room temperature dropped enough for the knob to open > 40% . Thanks.

hugbilly

I think the Tado valves open fully as soon as there's a call for heat . . .

guardi

There are some conflicting reports on that, but, there are people who hear the motor operating for a very short time - too short to fully open or close, which imho ‘proves’ that it can operate using smaller steps. Tado mentioned it operates at steps of 5%:

https://community.tado.com/en-gb/discussion/comment/24475/#Comment_24475

samd

@guardi What happens on the way down towards closure on your valves in question. In other words could you not alter your schedules to start with a significant increase in temperature, say for 5 minutes and then revert to the desired level of heat?

guardi

Yes, that’s what I’m doing now. But, on cold nights the temperature drops and hits the setpoint multiple times per night. I’d have to configure a spike-like schedule for the whole night, super ugly.. also overshoots the temp regularly, depending on other heating demand.

It’s just like, I can’t imagine / it’s so disappointing that this minimum setting can’t be configured. No valve is the same. Different brands, different age, wear. I’d say most people should run into this issue without realizing it..

samd

@guardi I do think that we would notice it if we had the similar issue. To my knowledge this is the first mention I have seen on here in 18 months. However, lets keep it open and seek further ideas.

If you have measured the distance to 1mm, could you not try a shim of that thickness and recalibrate the tado device?

guardi

Ha yes, i did that also:) glued multiple 0.1/0.2 rings together. But, it’s a painful precise process, and it’s not reliable. Sometimes when the knob pin hits the ring there is still a little water flowing, sometimes there isn’t. It’s difficult or impossible to make this work reliably. Thanks for the suggestions though.