Messed up heating!

[Matt1]

Hi,

I've got a few problems with my central heating, so hoping someone can point me in the right direction. I have searched the forum to see if anyone has the same issues, and was shocked to see how crap Potterton is - so could be another case here.

Our bolier (Suprima 30) locks out quite a lot, but not in a consitent (or not that I've spotted) fashion that is making it hard to detect what is wrong.

The 3 port valve (so I've been told) in the airing cupboard is on it's last legs and makes a strange electrical/groaning noise when switched on - I have to manually push it over to the Central Heating side sometimes - I think perhaps the motor is struggling.

Anyhooo - the problems...
When we switch on the heating, sometimes it works, but mostly the boiler sits there showing no signs of life until I manually push the lever on the 3-port valve (another potterton unit) into position, at which point the boiler kicks in and all is well.

Sometimes it does it on it's own and there is no problems.

It dies mainly when we're using the system - so if we leave it off overnight, it automatically kicks in without a problem in the morning (when it's cold). Ask it to repeatedly come on in the evening, and it isn't happy!!

If I do not move the lever on the 3-port valve, then the boiler goes into Lock-out. Multiple resets do not work. The *only* way to correct it, is for me to remove power to the system, wait 2 mins and try again.

Problem 2!!
When it's all working - the temp of the pipes on the pump register at near 70 degrees, the water in the tank reads 60 degrees, which the thermostat is set to, but the water from the taps in the bathroom show at nearly 70 degrees.

This scalded us the other day, so a little worried.

I apologise this is a long message, but please help - I've no experience with plumbing.

How much should it cost to have a plumber replace a 3-port valve?


Many thanks guys
Matt.

 

[oilman]

the water in the tank reads 60 degrees, which the thermostat is set to, but the water from the taps in the bathroom show at nearly 70 degrees.

If it was ok once, then tank thermostat is suspect.

Others will need to help with the other problems.

 

[Matt1]

the water in the tank reads 60 degrees, which the thermostat is set to, but the water from the taps in the bathroom show at nearly 70 degrees.

If it was ok once, then tank thermostat is suspect.

Others will need to help with the other problems.

I tried putting a digital thermo reader against the tank where the thermostat sits and it read 59.8, which is close enough. It did switch off once it got to 60 - although I could have just been lucky that time.

I wondered if this fault was related to the main one I posted.

 

[oilman]

Where did you measure the tank temperature?
If it was next to the stst, try measuring at the top of the tank. If it was at the top of the tank, things start to get interesting as the water is getting hotter on its way from the tank to the taps.

 

[ckf]

Where did you measure the tank temperature?
If it was next to the stst, try measuring at the top of the tank. If it was at the top of the tank, things start to get interesting as the water is getting hotter on its way from the tank to the taps.

I measured next to the stat, as that's the only part that doesn't have this thick polyfoam cover over it. It's about a third of the way up the tank.

It does seem that the water gets hotter by the time it gets to the taps!
The tap temp seems to match that of the pump temp.

Nothing to do with the dying 3-port valve?!

 

[MANDATE]

You might be interested to know that motors for the mid position 3 way valves are about £10 from www.screwfix.com and £17 from Wickes.

 

[Matt1]

You might be interested to know that motors for the mid position 3 way valves are about £10 from www.screwfix.com and £17 from Wickes.

Thanks Mandate.
Do you know if the Potterton 3-port has a seal between the motor and value part?

I read somewhere yesterday that some of the Danfluss ones do not and you end up getting wet when replacing!!

What is the name of the part I am looking for? I don't expect it to just be called a motor - had a quick look on Screwfix, but not sure on what I need. I don't want the whole value assembly, but could only see those.

Also - how easy is it to remove one - never done it before, and the bloody thing is pointed away from me in a tight airing cupboard!

 

[MANDATE]

Sorry I'm not familiar with the potterton 3 port valve, but you should be able to remove the motor head without any leaks. The one I removed was a honeywell, but it was the potterton suprima 30 boiler. It's the 'synchron motor' you may need, but in my case the valve spindle was stiffish and a little WD 40 and some turning by hand solved it.
I've looked at the screwfix site but didn't see a motor for a potterton unless it's there under a code number.
When you get the correct motor, it shouldn't be difficult to change

 

[Matt1]

Sorry I'm not familiar with the potterton 3 port valve, but you should be able to remove the motor head without any leaks. The one I removed was a honeywell, but it was the potterton suprima 30 boiler. It's the 'synchron motor' you may need, but in my case the valve spindle was stiffish and a little WD 40 and some turning by hand solved it.
I've looked at the screwfix site but didn't see a motor for a potterton unless it's there under a code number.
When you get the correct motor, it shouldn't be difficult to change

There are quite a few openings on the valve where I could squirt in WD40 - can I do this, or do I risk damaging it? Or would this be pointless?

From the sound it make, it does sound stiff.

 

[breezer]

i searched for you and came up with this and this

 

[Matt1]

i searched for you and came up with this and this

Thanks


Do you think this could be causing the boiler to lock out though?

 

[MANDATE]

I think the WD 40 will help, but you will need to operate the valve by hand for it work itself in.
I can only find details of potterton valves and valve actuators on www.mjtcontols.co.uk. I take it the 'actuator' is the complete head assembley so you must be able to remove it for examination

 

[Matt1]

I think the WD 40 will help, but you will need to operate the valve by hand for it work itself in.
I can only find details of potterton valves and valve actuators on www.mjtcontols.co.uk. I take it the 'actuator' is the complete head assembley so you must be able to remove it for examination

I took the Actuator off - it's a sealed unit (with screws that I haven't a screwdriver for!)

How easy should it be to turn the valve by hand? I can turn it it easily enough, but it's still got some resitance to it. Also... does it matter which position I leave the valve in when I re-fit the actuator?!

I will have to purchase a complete actuator, but before I do - can someone tell me if this could be causing the lockouts on the Boiler if this part is faulty?

Cheers.

 

[MANDATE]

The valve should be easy to turn with very little resistance.
The valve spindle will probably have a flat on it so it cannot be assembled wrongly.
As you may know the problem of lockouts on the potterton suprima range is quite high and it is highly likely the cause is the pcb where the soldering of the terminal posts seem to crack. I had months of intermittent lockouts on a daily basis until I fitted a new pcb.
I cannot see how the diverter valve will cause the boiler to lockout as it takes up one of three positions Hot Water/ Central Heating /or Mid Way, but if you had hot water but no central heating or vise versa then I would suspect the valve is not responding to the cylinder stat or the room stat

 

[Matt1]

Oh well it was worth a try!!

I was told that perhaps the diverter valve was not reporting which position it had got into quickly enough and the boiler timed out - as I wasn't sure either way on this advice, I thought I'd ask here.

It just seems strange that if we power-down the boilder (remove the fuse) and wait 10 seconds, it all works again when we switch it back on!

For such a new boiler this is sodding annoying.