Worcester Heatslave Stays on for about 30 mins then goes off.

[e5c0rt.mk1]

Hi,
My sister moved in her first house on Friday. The heating wouldn't work, we thought it was out of oil but about half an hour later it came on by itself, however it was only heating HW not the CH, the only way to get the CH to work is to manually move the diverter valve, the radiators then got hot.

However after about 30 mins of it working, it went off. The lockout light didn't come on, it just turned off. Then it kept blowing the fuse on the boiler circuit board, turned out the water pump in the boiler had broke so i replaced it with a different one and the boiler fired up again. But the CH only comes on if you manually move the diverter valve.

Then after about 30 mins of it working it just switches off, the lockout light doesnt come on. Then after about 1 hour it comes back on by itself. it has been coming off and on like this all night.

There wasnt alot of oil in the tank, but we have since put about 5 gallon in, but it has made no difference

Does anyone know what the problem could be?

The boiler is a Worcester Heatslave 18/25 external oil Combi boiler

Thanks

 

[Burnerman]

The boiler is probably cycling like that as it keeps the Heatslave tank hot.
Have you considered replacing the power head on top of the diverter? It sounds like the motor that turns the valve has packed in, or the gears on the quadrant have stripped.
John

 

[oilboffin]

I'll go with that John it's just getting warm and stats turning it off with the actuator fixed it should be ok but needs the flow switch checking.Bob

 

[Terrywookfit]

Fookin 5 gallons of oil..........I'm out !!

 

[e5c0rt.mk1]

Fookin 5 gallons of oil..........I'm out !!

1000 litres of kerosene is getting delivered at some point tomorrow, it's a bit hard getting a 1000 litres of it on a sunday !!!

The 5 gallon was took out of my parents tank which is nearly empty so that why i couldn't have any more.

The diverter valve feels like its working when i move it but might have to take it off and check it, why would this cause it to keep going off though ?

Thanks for your help so far

 

[oilboffin]

It's probably not touching the micro switch in the acctuator to set the pump going,Or the micro switch is duff.

 

[oilboffin]

Hello Terry my friend how are you keeping

 

[oilhead]

Are you sure you don't have a room stat that is holding off the diverter valve? You need to follow the fault finding chart to establish what is working and what is not. The boiler will keep the slave tank up to temperature if hot water is selected. If the pump is not moving water properly then the boiler wil do exactly what you say.
When you say you have changed the pump for one that is a different one, IIR correctly, the pump on this a special OEM unit. Also the diverter valve is a Drayton M series which is not the most reliable unit. the synchron motor iss replaceable on the actuator which could be all that is wrong with it but make sure you have power to it first. Also, what did you replace the fuse with? It should be a fast blow on the PCB, but also check the fuse in the supply as this usually blows first if it is the correct rating.

 

[e5c0rt.mk1]

She does have a room thermostat, it is set to 35 degrees (the highest setting) but it makes no difference. Could i disconnect this from the boilers circuit board, or would it just not work at all then ?

The pump head removed was a grundfos 15-60, i replaced it with a grundfos 15-50 pump head as my dad had a spare, i couldn't get a 15-60 as it was Sunday and everywhere was closed.

The fuse was replaced with the correct fuse

 

[oilboffin]

Here's a quick test take off the top of the elec panel and disconnect the flow switch if the diverter moves over the flow switch is goosed,if not then replace actuator.Bob
Be careful the tips in the board are live.

 

[e5c0rt.mk1]

Well i think i have fixed it tonight, took the thermostat receiver thing, what is screwed to the wall, apart and noticed it had 2 L.E.D's in it but only the red one was coming on. Put some new batteries in the thermostat and reset it, and the green led lit up on the receiver on the wall, and the boiler came on. Its been on for about 2 hours before i left, and is working great, the HW is VERY HOT, CH is hot, and when you alter the thermostat the boiler goes off and on accordingly.

Thanks again for your help

 

[Agile]

Working with the oil level virtually empty and pouring in just 5 gallons is seriously risky.

At risk of disturbing and sucking dirt from the bottom of the tank into the boiler!

I always advise those who effectively empty their tank, to let it settle for a few hours after a delivery to a nearly empty tank.

Tony

 

[oilboffin]

Well done oil head I must confess I thought you were barking up the wrong tree,but you were
right,it's something for me to look at in the future.Bob

 

[oilhead]

Well done oil head I must confess I thought you were barking up the wrong tree,but you were
right,it's something for me to look at in the future.Bob

Thanks, Bob.
As you will be aware, there is a logical sequence to oil combis operation. A lot of the time, too many people start in the middle and are already up th e wrong path. The fault finding charts are very good on the Worcesters. What we never know on here is exactly what the set up is with these problems until it is eventually wrung out through many posts. Experience is always the best tutor, and it doesn't always need to be your own.

 

[e5c0rt.mk1]

IT'S BROKE AGAIN

It comes on for about 2 or 3 mins then goes off, and wont come back on. The lockout light doesnt come on. If you turn the hot tap on it still doesn't come on.

I have tried reseting the room thermostat, bypassed the timer switch on the wall, checked all the connections on the boiler circuit board, and still nothing.

Anyone got and ideas of what it could be?