When I had problems with this boiler's DHW only reaching around 35C late last year I got great advice here for which I'm extremely grateful and hoped not to be looking for more!
Sorry for the long history but it may be relevant. Late last December, diverter recon kit fitted but it didnt improve DHW temp problem. Diverter motorised valve assembly replaced as the leaky diverter valve had knackered it - now the DHW water would reach around 55C then flame would go out, water cooled down, then reignited, doing this over and over. Never any error codes. The engineer changed various parts including hot water thermistor, main PCB and possibly analogue pressure switch. He had the heat exchanger out several times and got a few bits and pieces of black gritty stuff out. CH was and is still ok.
It seems that after one of those times, or coincidentally, everything was suddenly fine but he admitted he didn't know what he'd done to make it work. It has been working properly for past two months and then overnight the flow to the hot taps although hot is now low.
Quite soft water area. System was chemically flushed and filter fitted May 2015. Some years ago the boilers inlet/filling valve would only allow a trickle in to top up system, so boilers own filling loop was bypassed.
Cold water flow is around 13 l/min at cold taps and is ok near inlet to boiler. Hot water is 6 l/min at hot taps. When a hot tap is turned on the flow is momentarily a bit faster then immediately slows.
Could it be one of the following?
3 position inlet/filling valve has developed an additional fault?
I read that for Linea 24,28 & Plus 'These appliances are fitted with a hot water flow restrictor' - but where is it and could it be that?
Water flow regulator gunged up?
Heat exchanger gunged up?
Many thanks for reading this!
Jim
Sorry for the long history but it may be relevant. Late last December, diverter recon kit fitted but it didnt improve DHW temp problem. Diverter motorised valve assembly replaced as the leaky diverter valve had knackered it - now the DHW water would reach around 55C then flame would go out, water cooled down, then reignited, doing this over and over. Never any error codes. The engineer changed various parts including hot water thermistor, main PCB and possibly analogue pressure switch. He had the heat exchanger out several times and got a few bits and pieces of black gritty stuff out. CH was and is still ok.
It seems that after one of those times, or coincidentally, everything was suddenly fine but he admitted he didn't know what he'd done to make it work. It has been working properly for past two months and then overnight the flow to the hot taps although hot is now low.
Quite soft water area. System was chemically flushed and filter fitted May 2015. Some years ago the boilers inlet/filling valve would only allow a trickle in to top up system, so boilers own filling loop was bypassed.
Cold water flow is around 13 l/min at cold taps and is ok near inlet to boiler. Hot water is 6 l/min at hot taps. When a hot tap is turned on the flow is momentarily a bit faster then immediately slows.
Could it be one of the following?
3 position inlet/filling valve has developed an additional fault?
I read that for Linea 24,28 & Plus 'These appliances are fitted with a hot water flow restrictor' - but where is it and could it be that?
Water flow regulator gunged up?
Heat exchanger gunged up?
Many thanks for reading this!
Jim