I have a puma 80e and all of a sudden it is increasing in pressure with heating on to 3 bar,this activates the pressure relief valve and obviously I lose a lot of sytem pressure. I have been topping up back to 1.5 bar but over night with the boiler off I have lost a lot more from the system and it has gone through the prv. This means now not only can I not use the ch but can no longer get hw as the increase in pressure on demand pushes out the water through the pvr. Are there 2 problems and is it worth tackling one before the other? Thanks