Kingfisher MF Boiling Up

[Steve1967]

My view is that there is some kind of intermittent fault in your boiler!

They are so stable that they can be operated with no flow at all and just sit there keeping themselves hot by firing up for a few minutes every 15 min or so.

Converting to a fully pumped system would be much more efficient, give faster HW heatup and save gas costs. But not solve your problem

You did add heat transfer paste to the temp sensor point didn't you?

Tony

Hi Tony,

No, i didn't but asked the plumber to do it when he serviced the boiler but had a look earlier and it's the same as I left it. I've just nipped down to Plumb Centre and got a tube but when I unclipped the thermistor the two wires with the 'bulb' at the end were 'squashed' around the body of the thermistor. There is a hole in the 'socket' where the thermistor sits; should the wires and bulb be pushed through or is it ok to 'coil' the the two wires connected to the 'bulb' into the socket?

What exactly does a thermistor do and how much (and where) should the thermal paste be applied?

It's all a little academic at the moment as one of the wires connecting to the buld has come off so I need to order a replacement thermistor anyway but will need to know when I fit the new one.

thanks again,

Steve

 

[Agile]

I dont think the wires are insulated and so should be kept apart.

The socket should be filled with heat transfer paste and the sensor pushed in in one single movement to avoid creating a "hole" in the paste!

Best to buy it at Maplins I would expect!

Tony

 

[Steve1967]

I dont think the wires are insulated and so should be kept apart.

The socket should be filled with heat transfer paste and the sensor pushed in in one single movement to avoid creating a "hole" in the paste!

Best to buy it at Maplins I would expect!

Tony

Thanks Tony,

You're right, the wires are uninsulated so I will keep apart. I've ordered a replacement from AK Gas Spares but needed the right directions to ensure I fitted it correctly so thanks again for your help

Steve

 

[gaswizzard]

Are you suggesting for the OP to remove front case Tony?

 

[gaswizzard]

I used to convert to pumped using a second pump for about £240.



Tony

How would you do that then? , would you install the HW circulator without isso valves? ,

 

[Agile]

With iso valves in case of maintenance/replacement.

 

[Steve1967]

Are you suggesting for the OP to remove front case Tony?

Hi gaswizzrd, I think Tony is just being realistic, there's two screws holding the front panel on and the thermistor unclips.

I'm simply just going to do it myself, although I have a feeling it's not going to help the situation. The gas and mcb will be off when I do it.

We all do things may be we shouldn't and disconnecting a couple of wires is as far as I would be prepared to go.

If you've got any thoughts on the symptoms it would be good to get some additional feedback.

Thanks,

Steve

 

[gaswizzard]

With iso valves in case of maintenance/replacement.

So where exactly would the circulator be situated? , obviously not on the flow or return from boiler to HW tank as the isso valves will be in the direct path of open safety vent/cold feed , so where would you position this 'extra' £240 pump?

 

[gaswizzard]

Are you suggesting for the OP to remove front case Tony?

Hi gaswizzrd, I think Tony is just being realistic, there's two screws holding the front panel on and the thermistor unclips.

Front case is on the MF RS/CF is a combustion chamber seal , now Tony takes a dim view of DIYers removing combustion door , why would this boiler be any different?

 

[Agile]

I do take a dim view of DIYers opening boiler casings but this one already has, employs an RI to service the boiler regularly and is being very linited with what he is attempting to do and if he follows my advice on correctly fitting the sensor then he will have a safer boiler afterwards!

I used to fit the pump in the return from the cylinder. The vent remains unrestricted and the return ( as well as the vent pipe ) is available for the cold feed to flow to the boiler under all normal operating conditions.

 

[gaswizzard]

I used to fit the pump in the return from the cylinder. The vent remains unrestricted and the return ( as well as the vent pipe ) is available for the cold feed to flow to the boiler under all normal operating conditions.

Rubbish , I will guarantee EVERY circulator you fitted like this would have water pi$$ out over the open safety vent , unless of course you raised the vent pipe at least 4m over the F&E cistern.

In all the years I've been in this trade i've not yet seen a circulator fitted on the gravity return from cylinder to boiler.

 

[Agile]

Not seen mine then!

But be aware that I only needed to run them on setting "1".

 

[gas112]

GW be careful contradicting Agile he will say your being abusive . If he cant stick to the rules about encouraging diy gas advice perhaps a ban is in order

 

[slapper]

I,ll bet a pound to a pinch that the Boiler and associated pipework is partially blocked or scaled up.

 

[Steve1967]

I,ll bet a pound to a pinch that the Boiler and associated pipework is partially blocked or scaled up.

Thanks Slapper, it's been getting progressively worse over the last couple of years and now it's nearly every day so I guess a slow build up over time does seem a possibility.

Just don't want to blow £300.00 on a flush if it's not going to work. as Tony mentioned in earlier post we really need a heating engineer good with both plumbing and electrics to check everything over and then if there is no component/electrical issue go for the flush.

Our problem is actually locating a engineer in West Berkshire (Reading/Newbury) who can do both so if any of you chaps can recommend some-one please feel free)

Thanks again,

Steve