Question for Weargas

[MarkGibson]

Weargas sorry to be a pain but you seem to know a lot about the worcester heatslave 9.24.

I replaced the flow temp sensor on my boiler and its still doing the same thing. hot water running for about 10-15mins and then cutting out.

Just wondering if you can think of anything else it may be?

About 3 years ago had the same problem, took to bits and found that the overheat sensor, next to the pump overrun was loose, tightened it up and its worked ever since then up unitl now that is.

This is what makes me think it could be this sensor thats sending a faulty reading back to the gas valve?

I have ordered a thermometer so I can check the actual temp of the pipework coming out of the heat exchanger to see if it is cutting out genuinely or not.

Any help/advise of you guys is greatly appreciated, and will keep the missus off my back.

Mark

 

[weargas]

It's probably one of 2 things.

faulty overheat stat, it may be cutting out at too low a temperature. when you get your thermometer you can check that. I think the cut out temp on the worcester o/heat stats is 92°. you shouldn't run a room sealed boiler with the casing removed.


scaled/fouled dhw heat exchanger, the cold inlet simply isn't taking the heat from the primary water. this means that the dhw thermister will be telling the gas valve to fire at full rate which could result in overheat. you can drain the boiler, remove the heat exchanger and descale it/wash it out. this may help the overheat but probably won't return the heat exchanger to 100% i.e. your hot water won't be as hot as it could be.