Potterton Perform 24 Boiler - Lack of Hot Water

PhilTallon · 2 December 2017 at 3:32PM

Hi I have recently encountered problems with hot water with my Potterton Performa 24 boiler. I noticed there was a leak from the DHW Pressure differential valve After a engineer came and sorted this. He mentioned the Plate Heat Exchanger was scaled up so would need replacing. After not coming to fix the problem I call out another engineer and explained the situation. He was unsure that this was the problem but explained i was only going off the previous engineer advice. So I ordered the new Plate and this was fitted. although when removing the old one was advised there didn't seem much blockage. His diagnosis was that there was alot of gunge in system and would need cleaning out. So a cleaning agent has been added into system and advised to keep central heating running on low to start cleaning system then in a week or so time would come back and a magna clean system to be added. For few days the hot water was back, although water at hottest when not running tap on full. But now after 4 days the shower does not remain hot and even running tap in kitchen doesn't stay hot constant. Also noticed at times the flame only lights on boiler for short time then goes out and on and off after that.
I'm not wanting to keep throwing money at it without some sort of confirmed diagnosis. As both engineers say its a good boiler (Over 13 yeras old)
ANY ADVICE WOULD BE GREATLY APPRECIATED