Worcester Heatslave keeps locking out

Goulders · Posted: Sat Mar 12, 2011 6:25 pm

A friend of mine is trying to sort out a problem with her boiler. It is a Worcester Heatslave 15/19. She recently ran out of fuel and on refilling the oil tank, the boiler kept locking out after around 15 mins. I have had a look and oil is getting to the pump. I have vented the pump to ensure there was no air and all was fine. However, I also found that the CH pressure safety valve was operating and the gauge was at 3 bar. The water wasnt pouring out, but a steady/slow flow was present. I then found that the filling loop had been left open (for several months!!). I have switched the filling loop off and the pressure is now at around 1.25. It doesnt matter whether DHW or CH is individually calling for heat, the boiler still locks out after around 15 mins. Any ideas?

oilhead · Posted: Sat Mar 12, 2011 9:35 pm

Try the oil pump solenoid valve

Goulders · Posted: Sun Mar 13, 2011 7:32 am

oilhead wrote:

Try the oil pump solenoid valve

Is there a way to test it?

oilhead · Posted: Sun Mar 13, 2011 10:16 am

Before starting, measure the resistance reading accross the coil. Should be around 2.7K. Run the boiler until it locks out and measure again. If no continuity, coil needs to be replaced. They fail when hot.

Goulders · Posted: Sun Mar 13, 2011 9:49 pm

oilhead wrote:

Before starting, measure the resistance reading accross the coil. Should be around 2.7K. Run the boiler until it locks out and measure again. If no continuity, coil needs to be replaced. They fail when hot.

Cheers for that. Will give it a go.

Goulders · Posted: Mon Mar 14, 2011 8:44 pm

Spot on. Solenoid has been changed. Works great. Thanx very much.

oilhead · Posted: Mon Mar 14, 2011 8:53 pm

Glad it's sorted. Being as you've saved a call out fee, how about a contribution to Red Nose Day?