Powerflusher changed direction of CH pump: which is right?

[dnrichard]

Hi

I just discovered this forum. I hope somebody can help me out.

I just had my CH & HW system power flushed and the guy told me the pump was on the wrong way so he replaced it the right way up. The Potterton Kingfisher 2 boiler, pump and motorised valve are all next to each other in a small brick building on the back of the house so they are easy to get to. It's true that the pump looked like it was upside down and now it looks like it is the right way up but was it really pumping the water the wrong way through my system for the last five years (when it was fitted as a replacement) or is it now pumping the wrong way?

The CH & HW are working great with the pump on the new way round (the power flush did a great job).

I did, however, get overflow from the F&E tank. I've had overflow before but not this much. At the weekend I went to the F&E tank in the loft and it was full. It was nearly impossible to get to and suspecting an ancient ball cock valve I eventually removed the tanks completely, cleaned it out, fitted a new ball cock and put it back in place. All is well. But...

1. Is the pump now on the right way? Should it be pushing water through the motorised valve or sucking water through it?

* The pump is fitted vertically with the top end going to the boiler and the bottom directly to the motorised valve.
* The pump is now the right way up and going by the direction of the arrow it appears to be pumping water into the top of the boiler by sucking it through the motorised valve.
* It used to be the other way up and therefore was pumping water from the top of the boiler through the motorised valve and then on to the CH & HW circuits.

2. Is it ok to have a constant, small, circulation of water through the F&E tank?

When the CH comes on a small flow of water comes in through the Expansion pipe. It gets hotter as the water in the system is heated up. I checked the flow out of the tank through the Feed pipe and a similar amount appears to be exiting the tank. The tank does not appear to be filling up. But, over time the water in the F&E tank heats up.

Thank you for any help anyone on here can give me. If you need any more info then I'll take a look and get it for you.

Richard.

 

[Lower]

You certainly shouldn't have a flow of water through the F&E tank. If nothing else you will be constantly oxygenating the water which will increase the corrosion rate in the system.

Did it constantly pump over before the pump was turned the other way?

 

[Agile]

Without seeing the system its impossible to say.

More recently the flow from the boiler went first to the vent over the F&E tank and then the pump towards the motor valves.

Earlier systems used to pump back to the boiler on the return.

See which pipe on the boiler gets hottest and see if thats the boiler's flow pipe.

Pumping over will rapidly get you back to needing another power flush.

It can also cause pin hole leaks in your rads within weeks ( or even days! ).

You have been warned! Its important that its sorted out quickly!

Tony Glazier

 

[jackthom]

It does sound as if the pump may now be the wrong way round.

It's normal for the pump to be taking water from the HOT output side of the boiler and sending it towards the motorised valve and radiators etc.

The vent pipe which goes up to the F&E tank should be connected somewhere on the low pressure side of the pump, near where it connects to the boiler.
With the pump the wrong way round this would end up higher than atmospheric pressure and could result in F&E tank overflow.

Edit: Tony beat me to it.

 

[bathjobby]

As already stated you are constantly oxygenating the water which will lead to corosion (C/H inhibitor solutions work by removing the oxygen from the water), wasting your money and condensation and damp in the area of the tank.
Read my update here on the first steps to take for fixing this:
//www.diynot.com/forums/viewtopic.php?t=268548

 

[dnrichard]

SNIP It's normal for the pump to be taking water from the HOT output side of the boiler and sending it towards the motorised valve and radiators etc.

The vent pipe which goes up to the F&E tank should be connected somewhere on the low pressure side of the pump, near where it connects to the boiler.
With the pump the wrong way round this would end up higher than atmospheric pressure and could result in F&E tank overflow. SNIP

What a great forum. Thanks for the replies. I cannot see where the vent pipe is attached because all the pipes disappear behind the boiler and flue and it's completely inaccessible. However, what you say makes sense - if the first thing after the pump is now the vent pipe just before it's attached to the boiler then I can understand why it's pushing water up to the F&E tank.

It also instinctively makes sense for the pump to pump water towards the motorised valve and into the respective HW and CH systems and not suck the water out of them.

Ok, I'll get the guy back to turn it back round. He won't have to drain the system again will he?

Thank you again for your replies.

Richard.

 

[misterdubya]

Was this guy cheap per chance?

 

[dcawkwell]

The arrow on the pump should point away from the boiler to towards
the motorised valve.

Expansion and feed pipes should be connection between the boiler
and the pump.

The pump should be on the flow pipe of the boiler not the return.

 

[dnrichard]

Yup. He's coming round at 8am tomorrow to fix it back in its previous direction.

Thanks for all the advice. Really great.

Richard.

 

[petit_pablo]

Arrow on pump should point at the motorised valve.

Expansion pipe shouldnt have running water from it.

Get him to turn pump round correct way then see what happens with expansion pipe after that.

 

[Boilerman2]

If the pump is in the Flow (pipe leaving boiler at TOP of water jacket) the arrow on the back, or side of pump should point away from the boiler.

If the pump is on the Return (pipe leaving boiler at bottom of heat exchanger) the arrow on the back or side of the pump should point towards the boiler.

do not take any notice of the arrows around the bleed screw on the front of the pump, this arrow mearly indicates the direction of rotation of the pump drive

 

[dnrichard]

Yes. Definitely he's put it on the wrong way round. Oh well, easily fixed.

Interesting that the system still works fine (apart from the flow through the F&E tank). I've turned it off until he fixes it though.

Thanks again.

Richard.

 

[Agile]

Did he come at 8 am today and reverse it?

What comment did he make?

Is it still pumping over?

What inhibitor did he add?

Tony

 

[dnrichard]

Hi

It took a few days for him to come but he's just been this afternoon and swapped it round. I don't know what inhibitor he added but I know he put some in when he refilled it. I've previously used Wickes own brand. Anyway, it all came back on and off he went.

Now, there's another problem that was the reason I got it power flushed in the first place. It's a problem made all the more odder by the fact that with the pump on the wrong way round the CH and HW systems were working great apart from the F&E circulation.

I was using electricity to heat the water over the summer and when I turned the heating back on last week the boiler was lighting but going off after a few minutes. I though the pump was maybe gone and the system needed power flushing. One power flushing later and the pump worked perfectly the wrong way round. The whole system worked the wrong way round.

But now the pump is back the right way round, and the way round it has been for the last six years successfully, I now find that the boiler fires up and then after a few minutes turns itself off. I think the pump is still going but the water it's pumping round is not getting hot.

What on earth could this be? It all worked when the pump was on the wrong way round.

 

[jackthom]

Seriously if your man can't hang around long enough to check that the heating actually heats up a few radiators he's a waste of space.

It's not normally necessary to drain the whole system to remove the pump.
Are there taps either side of the pump and have they both been re-opened?