Worcester 280 RSF Prob

[a_girl]

On thursday daytime rads and hot water went off. Thursday nite, turned boiler off at panel and wall for hour or so then pressed reset on panel and switched to ch&&hw.

Boiler fired up ok and got a bath and hot rads but after a couple of hours water ran out and rads went cold.

Switched off for hour or so again then topped pressure up to 1.2-1.5 and booted onto ch&hw.

Again it fired up ok and got dishes and hot rads but after couple of hours again water ran out and rads went cold.

Each time, to get it booted i've had to press reset and before resetting i hear water running when a rad dial is turned up but there is just no demand.

Does this sound like the overheat thermostat? I'm just using the rad settings i normally use so didn't think it is an overheat.

Any information anyone could offer would be much appreciated before i have to call a man in the know! £££££

Thanksalot

 

[DP]

First things first. Boiler is not a computer and does not need booting.

Boiler will run when any hot water demand is made or there is a call for heat

It would appear you are losing system pressure. If you on the other side of the wall where the boiler is mounted, you should see a flue terminal as well as a 15mm pipe sticking out of the wall.

When you pressurise the boiler, pressure gauge rises to indicate water pressure. It should indicate 1.25 to 1.5 when cold. Does the pressure stay at that level when you do NOT use the boiler? When you make a heating demand, does the pressure rise? If it does, can you see water running out of the 15mm pipe sticking out of the wall as mentioned before?

I suspect this boiler has two reset buttons. One is for overheat which will reset with a click. This button pops if the boiler gets too hot which it might be if you are running short of water. Other is a a flame failue/ ignition sequence failure reset that pops if burner does not ignite within 10 seconds. I suspect a red light shows for this. Would have to check the manual for this but another regular might correct me

 

[a_girl]

Sorry, in my term booted - i meant fired up.

I think your system pressure comments are it as the boiler does ignite, and stays for longer than 10 seconds.

In the off position, what pressure would you recomment on the visible dial?

Thanks again.

 

[kevplumb]

system pressure cold should be 1 to 1.2 bar

 

[DP]

Do you mean you can see water dripping from the 15mm pipe going through the wall?

In the rarified higher latuitude of Scotland, I pressurise to 1.5. It can be 1.2, even less or more- as long as it does not go too low or well past 3

 

[a_girl]

well since my last post i've had a leak in the automatic air vent, which has been replaced and was choked full of dirt. then the system wouldn't fire up so the printed circuit board was replaced.

it fired up no probs after that was replaced but we noticed the thermostat dial on the front of the boiler was just spinning, it was then replaced and we now have a definate min and max stoppage on the dial but it's still not working

we have to press reset (still) to get the boiler to light, then we only get around 30 mins of water when the system shuts off and the water runs cold. and after around only10 mins of being on, the temp is away up at 80.

any suggestions here? as my engineer is baffled and is consulting bosch/worcester for advice as it's doing his head in.

thanks in advance for your expert information!

 

[ChrisR]

When in doubt blame sludge. Poor circulation leads to overheats. Weak pump or restricted heat exchanger(s). Wouldn't fire up so changed the pcb??? All of a sudden??? I must remember that one, £ove£y idea!

 

[a_girl]

It was burned out that's why it was replaced. I still have it and can see that's why.
Dunno but maybe the water dripping behind the panel could've contributed.