Hot Water but No Heating - Potterton Kingfisher RS50

[pancaz]

Hello

We have Potterton Kingfisher RS 50 Boiler at home which is controlled by Honeywell's time device to control Water and Radiator heating. It was working good until yesterday.

Now we have no heating but still have hot water. I noticed that when I put it on for the heating, it does not start/burn as it used to. Also I can not hear any sound of water running through the pipe when I put heating on.

Actions I have taken so far -

1) Made sure that Heating is on continuous
2) Have reset the boiler timing etc (from Honeywell's timing pad)
3) Tried to light the boiler using control switch and ignition. It burns but as soon as I leave the control switch, fire goes off.

Any help would be highly appreciated.

Thanks

 

[petertheplumber12]

You must have a 2 or 3 port valve in the airing cupboard, you need to make sure that is working properly and giving the boiler the right info.

 

[pancaz]

Hi Peter

Thanks for the quick reply. I just checked the airing cupboard and there's only one valve which is controlling cold water flow either from or to the hot water tank.

Also, I checked if there are any valves near the boiler. There are two either side of the pump. and they seem to be OK

regards

 

[petertheplumber12]

Then you have what is called gravity hot water and pumped heating, in which case does the pump run when heating demand is activated?
It sounds like the pump has failed and you need a new one, the boiler fires up but as soon as pipes heat up it switches off because the pump doesn't get rid of the heat.

 

[pancaz]

Hi Peter,

Thanks again. No Pump does not run when put on heating, but I am surprised why it would not as it's a Brand New Pump and was changed only last week.

Kind regards

 

[petertheplumber12]

Now it gets a bit tricky, when you call for heating the pump needs testing with a multi meter to see if a voltage is going to it, and that the wires are connecting good. If no voltage then the fault is programmer or connections, etc. If voltage is good then the pump is stuck or faulty, unscrew the shiny steel cap with a large screw driver, and then with a smaller driver twist the slotted shaft clockwise a quick spin, if it turns freely it isn't stuck, if stiff turn until it's free and make sure some water dribbles out, to prove that it isn't running dry.

 

[FiremanT]

Now it gets a bit tricky, when you call for heating the pump needs testing with a multi meter to see if a voltage is going to it, and that the wires are connecting good. If no voltage then the fault is programmer or connections, etc. If voltage is good then the pump is stuck or faulty, unscrew the shiny steel cap with a large screw driver, and then with a smaller driver twist the slotted shaft clockwise a quick spin, if it turns freely it isn't stuck, if stiff turn until it's free and make sure some water dribbles out, to prove that it isn't running dry.

Alternatively,phone the plumber who changed the pump!

 

[petertheplumber12]

That's not fair fireman, That was going to be my next suggestion. Said he smiling.javascript:emoticon('')
Just had a thought what if one of the pump valves isn't open fully?

 

[pancaz]

Thanks a lot, I guess I will call the plumber to come and have a look. too technical for me thanks for your help!

 

[petertheplumber12]

Good luck, he shouldn't charge, and a Happy New Year.

 

[pancaz]

Thanks Peter. Happy New Year to you too

 

[petertheplumber12]

Once I fitted a new pump on a new system and 2 weeks later I had to change it, it had an internal electrical fault, replaced free of charge , not my fault but nothing from grundfoss for my effort or time.

 

[pancaz]

Hi. My plumber came to look at the boiler yesterday. He changed a wire which he said is a sensor to activate ignition. He then bleed all the radiators. And boiler fired up. It worked well all night but now trippping again. I have to ignite it manually. I also noticed that water pump is quite hot. I talked to the plumber over yhe phone and he said we may need to flush the entire system and askinh 400 pounds for that. We have already spend 200 pounds on sensor wire and pump. Any suggestions please

 

[petertheplumber12]

That best way to test if heating needs power flushing is once the rads have heated up go to any fairly long rad and feel the temp at the top then run your hand down and feel the rad near the bottom in the middle, it should be just as hot once it has heated up. feel the rad in the middle spreading hands away from middle to the top and the sides. If the temp is hot all over then power flushing isn't needed.Try lowering the speed of the pump it is probably a 3 speed pump if it is on max speed drop it 1 speed and if it still heats rads ok then see if still gets as hot. Without looking at the system it is very difficult to tell whether there is much load on the circuit, how many rads etc. Pumps usually only get hot when they are running with not enough water in the system to cool them down, then they overheat and burn out.

 

[petertheplumber12]

Hi. My plumber came to look at the boiler yesterday. He changed a wire which he said is a sensor to activate ignition. He then bleed all the radiators. And boiler fired up. It worked well all night but now trippping again. I have to ignite it manually. I also noticed that water pump is quite hot. I talked to the plumber over yhe phone and he said we may need to flush the entire system and askinh 400 pounds for that. We have already spend 200 pounds on sensor wire and pump. Any suggestions please

If you have a pumped heating/gravity hot water it would be money well invested to change it to a fully pumped system, your system is very prone to getting air in the rads, and that makes sludge every time you bleed them, if rads are not to bad, drain the system while it hot and refill with a cleaning chemical leave it running for a week then re-drain and flush with fresh water then re-fill with an inhibitor. If you drain it every year and refill with new inhibitor every time you will never get enough sludge to worry about.