How to test relay and valve reach

Apart from the fact that is very poor design not to provide reach extenders,  how can I test weather the valve can reach the relay?

I have a house in which I need to decide what to install. I bought the relay, thermo and valves. But now need to know whether it is worth wiring it to the burner. Worth being, does the valve reach the relay.

I configured the relay, seems to work, but simply plugged it in using the USB on the relay before connecting to the burner. I placed the connected valve in various places and it seems that it quite quickly fails to connect. As in, distance of less than 15m, the connection between relay and valve is no longer there.

Is there truly no way of adding an extender, a second relay, a second hub or what not so that Netatmo can be used? Or should I simply ditch it, and look for a brand that has thought its design through?

For what it's worth, 2 have no signal, 4 very week, 2 are ok-ish, 1 is good. This is truly poorly designed, I would say.