Hi Everyone, this is my first post so I'd be really grateful for any help given.
The 3 amp fuse on my hw/ch system blew the other day, so I tried replacing it and it blew again immediately. I then noticed that the top of the pump housing was wet as the spindle end of the gate valve above it had been leaking.
To investigate further I removed the cover from the box on the side of the Grundfos 15-50 pump and noticed some moisture inside. I then separated the box holding the capacitor and speed control from the side of the pump body by undoing the screws and pulling out the 8 pin plug. I decided to try a fuse again at this point, which may have been a bad idea - anyway, it blew immediately with a flash from the disconnected box.
Next I separated the box from the mains wiring, replaced the fuse, and was able to fire up the boiler from the control programmer with no problems (I turned it off immediately) so I'm fairly happy all is ok with the rest of the system and the fault lies with the pump.
I then separated two parts of this box separating the plug and speed control unit from the outer cover and found water between these two parts. I couldn't detect any signs of moisture inside the pump body around the motor windings but it isn't easy to see inside this.
Now to my questions:
1) Is it possible that the electrics were shorting due to the moisture around the terminals of the 8 pin plug and that if I thoroughly dry this out and replace it all may be ok (once the gate valve leak is fixed, of course), or are the motor windings likely to have burnt out too?
2) Is the capacitor likely to have been damaged by the water shorting or by me powering up with the 8 pin connector separated from the rest of the motor? It shows no outward signs of damage.
3) If I need to replace the whole pump does anyone know if the Grundfos 15-50/60 is a good unit? - I can't find this on the Grundfos website, but there also seems to be an Alpha 2 15-50 which I'm guessing may have replaced the 50/60. Are all of these units the same physical size and interchangeable?
4) If I end up having to change the pump and its easier to remove the 4 allen screws and just change the head will a new diaphragm be needed and can these be sourced separately?
5) For future reference - the pump wiring is connected to a junction box and can only be operated when the programmer is switched on. Would it matter if I temporarily disconneted this, fitted a standard 3 pin plug with 3 amp fuse and ran the pump from a 13 amp socket using an extension lead? I may want to put some descaler into the system some time in the future and it would be useful if I could circulate the water in the system without having the central heating on all the time.
Thanks for any advice given.
The 3 amp fuse on my hw/ch system blew the other day, so I tried replacing it and it blew again immediately. I then noticed that the top of the pump housing was wet as the spindle end of the gate valve above it had been leaking.
To investigate further I removed the cover from the box on the side of the Grundfos 15-50 pump and noticed some moisture inside. I then separated the box holding the capacitor and speed control from the side of the pump body by undoing the screws and pulling out the 8 pin plug. I decided to try a fuse again at this point, which may have been a bad idea - anyway, it blew immediately with a flash from the disconnected box.
Next I separated the box from the mains wiring, replaced the fuse, and was able to fire up the boiler from the control programmer with no problems (I turned it off immediately) so I'm fairly happy all is ok with the rest of the system and the fault lies with the pump.
I then separated two parts of this box separating the plug and speed control unit from the outer cover and found water between these two parts. I couldn't detect any signs of moisture inside the pump body around the motor windings but it isn't easy to see inside this.
Now to my questions:
1) Is it possible that the electrics were shorting due to the moisture around the terminals of the 8 pin plug and that if I thoroughly dry this out and replace it all may be ok (once the gate valve leak is fixed, of course), or are the motor windings likely to have burnt out too?
2) Is the capacitor likely to have been damaged by the water shorting or by me powering up with the 8 pin connector separated from the rest of the motor? It shows no outward signs of damage.
3) If I need to replace the whole pump does anyone know if the Grundfos 15-50/60 is a good unit? - I can't find this on the Grundfos website, but there also seems to be an Alpha 2 15-50 which I'm guessing may have replaced the 50/60. Are all of these units the same physical size and interchangeable?
4) If I end up having to change the pump and its easier to remove the 4 allen screws and just change the head will a new diaphragm be needed and can these be sourced separately?
5) For future reference - the pump wiring is connected to a junction box and can only be operated when the programmer is switched on. Would it matter if I temporarily disconneted this, fitted a standard 3 pin plug with 3 amp fuse and ran the pump from a 13 amp socket using an extension lead? I may want to put some descaler into the system some time in the future and it would be useful if I could circulate the water in the system without having the central heating on all the time.
Thanks for any advice given.
