Potterton Netaheat 6/10 pump issues??

[sadsack]

Hi all,

Issue is with a Potterton Netaheat 6/10 boiler.

Everything was working fine until recent redecoration of small room, removed rad to decorate, replaced rad, and after bleeding rad pump started to make a very unusual sound, even though the central heating was turned off, but hot water was on, (due to timer).

Sound can only be explained as though the pump is not running at full speed. A rather difficult sound to

I asked my brother (who is a lot older than myself and hence had much more experience than myself) what he thought it could be, and he said that the pump should not be running if I have just the hot water on.
But this is how it has been for the last number of years.
This is the second pump to be fitted and is around 6 years old.
It just seems unusual after he said this to me that it does seem unusual for the pump to be running for both hot water and central heating.
I may obviously be completely wrong and this may well be how the boiler operates.

The pump is very hot to touch, also the pipe directly above the pump and below it is also very hot, but again this is not unusual.

There are two on/off switched below the wiring box, one is for the immersion, and the other (someone has written on it) "Central Heating 240v 3 Amp only"

If both H/W and C/H is on and this switch is turned off everything goes off.
I have tried it with H/W only and switched it off, again everything goes off.
The same with C/H.


I wouldn't say it was loud but you couldn't sleep in the same room as it.

The wife was the first to notice it, and it was as soon as we refilled the rad and bled it, that's when the noise started.
I have checked all the other rads in the house and made sure water is coming out and no air.

Would anyone have an idea they could throw at me,..... could this have been wired wrong from day one, or is it just coincidence that i replace one rad and this god awful sound comes from the pump.

Or is this a much simpler problem, and I am making a mountain out of a molehill.

any ideas would be very much appreciated as we are running off of the immersion at the moment.

Thanks

sadsack

 

[ChrisR]

he said that the pump should not be running if I have just the hot water on.

My older brother's a divot too when it comes to plumbing.

Probably, you didn't bleed all the air out. There's a screw in the middle of the pump - undo until you see some water.
Also there will probably be an air vent on the heating pipes which go into the side of the HW cylinder.

 

[sadsack]

Thanks ChrisR,

Yes I did undo the screw on the front of the pump, and a small trickle of water did come out, but it wasn't clear.....

Thinking about it, should I have had both h/w & c/h on when I did this cos if I remember correctly all that was on was the h/w.


Also the air vent that you mentioned is this an easy thing to see, cos I don't seem to be able to locate it.

I have decided to upload a pic to make things a little easier.

[GALLERY=media, 33390][/GALLERY]

Hope you can see it, never done this before.

thanks
sadsack

 

[bengasman]

If it is not an air problem, it could be corrosion residue restricting the flow.
It also looks like your pump is pumping downward, which is not conducive to getting rid of air bubbles.

I would suggest you don't ask your brother for advice on your heating; his knowledge is somewhat lacking.

 

[twgas]

Check the f&e tank, in loft, I would suggest that,either the ball valve is stuck or the cold feed blocked.

 

[45yearsagasman]

You have a Y Plan system and the pump SHOULD run on both hw and htg.
It is difficult to track down system noises and faults.It may well be your pump is noisy and there are many reasons for this.
With respect, you or your brother seem to have little idea on heating systems and the way they work.It would save you a lot of grief if you called a decent heating repairman who would be able to trace and repair the fault.
Your picture doesn't show the whole of the installation,but from what I can see it is not piped up in line with modern practices regarding the cold feed and open vent.

 

[misterdubya]

This is the second pump to be fitted and is around 6 years old.

That pump is never 6 years old

Mr. W.

 

[Agile]

I dont see how you can tell the age of he pump. Even if you could, some people fit old stock.

OP, I think there is a manual air vent fitted on a vertical pipe just in front of the pump.

Have you loosened the screw cap to let air out of it?

Tony

 

[sadsack]

Where do i start,

yes i did purchase the pump about a year before my son was born and he's now 5. And it was brought new from a plumbers merchants.

Yes I did open the screw on the front of the pump and it is working, but as i said all that has been done is a small single rad in a box room was removed for decorating purposes and replaced, refilled and bled.

as soon as it was bled that was when the noise started, and believe me this noise wasn't there before, this is a serious noise that you can here from all over the house, but dose seem to emanate from the pump.

I am starting to think sludge possibly, and maybe doing a flush of the system, by leaving the vents open and letting it flush through until clear water appears.

I used to have a "reputable" corgi reg gasman do my servicing until i found him trying to find some pipe work in the upstairs bedroom dressing table.... and now I find myself in a position of not knowing anyone personally whom I trust.

At the moment the boiler is being heating by the immersion heater.

Any pointers chaps..

would a flush of the system with the gas off, and the electric switched off, with all rads open help ?

 

[bengasman]

would a flush of the system with the gas off, and the electric switched off, with all rads open help ?

If you mean a simple drain down: no, not a chance.

 

[twgas]

did you

Check the f&e tank, in loft, I would suggest that,either the ball valve is stuck or the cold feed blocked.

 

[sadsack]

Thanks all for the replies...

Someone had mentioned to me about the rad tank in the loft, and that it may have run dry, luckily our loft is fully boarded and is easy to get to both the tanks.

The rad tank is fully operational, all except one little thing, after removing the lid and the lagging on top of the lid, it looks as if about a thumb full of lagging had dropped inside the tank, now I'm not gonna say that's the culprit, but it does seem very likely.

So i tied off the ball valve, as the stop cock is no longer playing ball, I then totally drained the tank and thoroughly cleaned it before releasing the string and letting it refill.
I waited to see how far it refilled and it was spot on the water mark.

But the water that i emptied out was absolutely filth, seriously disgusting, although it didn't smell at all, there seemed to be what looked like, what I can only explain as fish food flakes in there.

but as I said, there wasn't handful's of lagging in there just a couple of very small pieces.

I didn't drain the system as there seems little point, because if something has come down it will probably only make matters worse.

but at least I have a better idea of what has more than likely happened.

Also Sprayed copious amount of wd40 onto stopcock to see if that help loosen it,

Now it looks like I'm going to have to get someone in,

ttfn
sadsack

 

[ChrisR]

Your pump's a lot more than 6 years old.
Yes there's an air vent. The knurled top might be too stiff for fingers. Loosen it and water should come out. If nothing, you'll have to take the top off and poke a cocktail stick or something in to clear it. Then it'll squirt hot water so take precautions

 

[sadsack]

Thanks for that ChrisR,

We're only running off the immersion as and when needed at the moment, so when it's cold I'll have a look.

About the pump, could I have been sold a recon unit, (if such a thing exists in the plumbing world).?

ttfn
sadsack

 

[twgas]

now you've cleaned the f&e tank, and confirmed the ball valve is working, I'd suggest you connect a hose to a drain cock, open it up, while it's running go into loft to see if f&e tank is refilling.