heatslave 20/25 ch pump forced on

sparticus · Sep 5, 2012

hi,
i am trying to keep alive a workhorse of a boiler on its last legs. Following a 'spillage' when removing the CH pump for a bench test all sorts of problems/lockouts since. The water may have ingressed the 832.2 control box and the fan gets noisy. I have opened up and cleaned the control box but I am getting intermittent lockout after a few hours. Left to cool overnight the boiler burns for 10seconds then locks out every time repeatedly, until. re-seating the control box and giving it a thwack seems to cure it (for several hours), so a new one on the way.
My question is that to eliminate the CH pump I have connected directly to a separate plug so it is permanently spinning.
Is it OK to leave it like this, as I am not sure if the pump spins when in DHW mode?
Also the minute copper pipes on the thermostats, how sensitive are they as one bent but I managed to bend it back OK.
Because it runs for several hours I assume the basics are working. Any views on the above?
PS the original fault was DHW fine but CH would run for a few minutes and the burner would then stop, no lockouts DHW still fine.
I greased the divertor but still occasionally did it, hence removed the pump.
?

SimonG · Sep 5, 2012

Sounds like you learned the hard way about only working on the water bits with the burner out.

You'll struggle to 'clean out' a control box, but a hair dryer or a week on the dashboard of the van work wonders.

Yes the pump spins in dhw mode but only on demand i.e. getting store upto temp or running hot water.

Could be dodgy high limit or problems with the board, difficult to say without it being in front of me and having a good luck.
Sounds like you're getting ever closer to that new boiler.

diamondgas · Sep 5, 2012

As above plus there's a thermostat that controls the water circulation temp whilst heating the store! They're prone to issues! the copper "capillary" tubes are pretty robust. If split though then the stat they're connected to is useless!!

Leaving the pump on a plug won't harm the boiler, however it will up your bills as the boiler will periodically relight to keep the store hot. the boiler heatex will act as a radiator and draw the heat out of the store when the burner shuts off 🙂

Are you GSR?

DirksPlumbing · Sep 6, 2012

Had a few issues on systems lacking inhibitor with the diverter valve being stuck. Especially the greasy comment points that way. Never been able to get them back fully functioning. A replacement of the valve body was the only long term solution. If you are going there do not forget to keep a couple of pump valves and fiber washers at hand just in case.
Sounds by the time all the parts are replaced you got a nearly new boiler there. Have a careful inspection of the heat bank before you even go into ordering spares. And check the actuator as these burn out quickly if they can not move the diverter properly.