Have noticed over the last view days the process has slowed considerably. Normally, the boiler fires up soon after the room stat clicks in and it gets up to desired temp within a few minutes. Have noticed the boiler is much quieter when it does ignite (approx 10 mins after being switched on) and today took 40 mins to reach 65 degs. The only thing I've tried it a reset, but still the same. Any advice would be appreciated.