Ch Upgrade

I am having my back boiler removed and a condensing combi fitted. I understand that under new regs it is mandatory to fit a room thermostat to combi. My problem is that i dont want to rip up floor boards etc to route the wiring to the current thermostat. Would it be ok to fit one of those wireless thermostats like danfoss sell?

I will be removing the current system myself once the gas is disconnected. There is quite a lot of sludge in the system. What is the best way to clean this out before the boiler is fitted(system is currently indirect primatic).

Stuff on Flushing can be found in FAQ section, or Kamco site, or Fernox.
System condition is the responsibility of the boiler installer, so if using someone else talk to him first.

The wireless jobbies are fine - look at programmable thermostats, which will save having to buy a timer for the boiler.