Customer complaining on Luke warm hot water. On arrival checked for diverter valve problems. Seemed ok.
Plated heat exchanger had been changed two years ago so ruled that out for now.
Checked gas rate of meter with hot water demand,, that was fine at 21mbars.
Then with water control up high checked burner gas pressure. Book said 15mbars, actual on boiler being 10mbars. I checked it from initial demand, the manometer did not go to 15 then modulate down, it just went to 10 and stayed there. So, that is obviously the reason.
Gas valve resistances fine and so was hot water resistance at specific temps. The only way to get the water to get hot was to reduce flow.
I have read that this is a pcb issue. Opinions please, (they are 210.00 after tax!).
Plated heat exchanger had been changed two years ago so ruled that out for now.
Checked gas rate of meter with hot water demand,, that was fine at 21mbars.
Then with water control up high checked burner gas pressure. Book said 15mbars, actual on boiler being 10mbars. I checked it from initial demand, the manometer did not go to 15 then modulate down, it just went to 10 and stayed there. So, that is obviously the reason.
Gas valve resistances fine and so was hot water resistance at specific temps. The only way to get the water to get hot was to reduce flow.
I have read that this is a pcb issue. Opinions please, (they are 210.00 after tax!).