M
murphtheguv
I have currently passed my ACS qualification and decided to have a look at the problem with my worcester 28i. When calling for hot water the boiler fires up fine and the water gets hot. After approx 30secs of running hot water the boiler shuts down. With the hot tap still running (water gone cold) the boiler then fires up after about 5sec and continues to do this over and over again for the same time intervals. In central heating mode there are no problems. I Serviced the boiler to the manuals instructions and all ok. I took an uneducated guess and changed the hot water thermistor but this didn't solve it. Then i noticed the boiler stays lit when calling for hot water if the inner casing is off but soon as i tighten the last screw of the casing creating a seal the boiler shuts down. I suspect the fan but wouldn't want to be wrong again due to the cost. Any advice off some experienced gas engineers would be much appriciated.
