[Solved] Tuya Zigbee valve controller in a built in boiler. Signal attenuation issue?

Hello
I have fitted a Tuya valve controller on the water supply to the DHW boiler. That's the one on the left.The boiler in full plasterboard on the rack plus a lot of pipes in the revision:

Unfortunately, WiFi didn't get there. So I replaced the controller with Zigbee.It too is offline when the revision flap is closed.The flap looks like this:


The gate ( 5m distance) does not see it.So I inserted a Zigbee repeater inside. And interestingly the signal from the repeater as normal reaches the gate, but from the controller does not.I checked that the controller connects to this repeater, but unfortunately after closing the flap it becomes immediately offline. This is the first conundrum. I looked inside for the optimum place for the repeater, but this did not give anything. The flap has an aluminium frame.From the inside it looks like this:


These scabs are remnants of a mute sponge which I tore off, thinking that it contributes to signal attenuation. Could this frame on the flap be creating some sort of obstruction? Of course, with the flap open the signal is ok.I've run out of ideas:-( What else can be done?

palmus wrote:

The gate ( 5m distance) does not see it.So I inserted a Zigbee repeater inside. And interestingly the signal from the repeater as normal reaches the gateway, but from the controller does not.I checked that the controller connects to this repeater, but unfortunately after closing the flap it becomes immediately offline.

Can you describe this a little more clearly?
When you close the repeater flap what connection works?

The repeater<->gateway connection works. With the flap closed. The controller does not. According to the mesh rules, the valve controller should communicate with the repeater as an intermediary ( 20 cm next to it) and send it on, since it can't manage on its own through the walls. With the flap open or even tilted for about 25 cm, everything communicates nicely with the gateway.

Have you removed and added drivers from Tuya, so as to rebuild the connections?
Change the power supply to the valve, maybe this one "sows" interference and "nudges" the receiver in the valve.

Off, 10 sec, on for the controller, quick close of the flip.I check the connections on the gateway and see that the controller is connected with the repeater, the repeater is visible and connected to the gateway and the controller is not.Just a curiosity.
I will check the power supply.

You can still disconnect all other electrical devices in the vicinity for a test.
From the photo, I infer that the inspection flap when closed is very close to the valve controller?

Yes.About 5 cm.Unfortunately I can't turn the valve,and lack of space and possible leakage.I thought maybe cut off/tighten that wide strip of aluminium on the left to the minimum?

From the photos I estimate that the aluminium strip is away from the valve, although probably less than a wavelength. However, it is possible that the bigger problem is the radiation characteristics of the antenna from the valve and, on top of that, the material from which the flap is made. It sometimes happens that materials such as bathroom tiles on the wall perfectly block the signal of e.g. WiFi. We don't know what the properties of your plasterboard are, as I guess the inspection flap is made of this material. The differences can be very significant, e.g. in Poland and Germany these are boards with different properties (the German one is sort of more "ceramic").

The board is classic plasterboard, on the side plasterboard plus mineral wool, on the opposite side plasterboard plus tiles. I even put the repeater on this controller - nothing.The repeater has a "good" signal, the controller offline.It's possible that the antenna is in such a position that it is shielded by some kind of lich. But why doesn't it want to get out via the repeater???? Some kind of interference when the frame al is brought closer ?

It turned out that the door had a frame behind Al 2.5cm wide(!) And on top of that a frame embedded in the wall also 2.5cm.- The controller and the antenna were looking directly at the corner of the inspection hatch - a 5 cm wide strip of metal sheet - so not a bad screen. I tore the whole thing out, cut off the excess angle bar, leaving only a couple of slots for attaching the frame and the filling, the construction became filigree, but it helped.