Emonpi Radio going down

I have an EmonPi with a couple of TH temperature sensors transmitting to it. Most of the time it is fine and I get updates every minute or so, five minutes at the worst. But every now and again it goes down hard and no transmissions from the TH's turn up. 

The Emonlog feed system is working, since I'm getting updates from the CT1/2 sockets and the hard wired thermostat. There's just no data in the log from the TH nodes. 

The only way I can recover it is by running an update, which flashes the radio firmware and recovers the radio straightaway. However I can't imagine constant flashing is good for the device.

Is there anyway I can give it a kick without running the flash update?