Surging noise when CH runs!

pgatsky · 4 Oct 2006

I recently changed my pump (Grundfos UPS 15-50) and followed the correct procedures i.e drained system throughly, flushed out all the crap and added Sentinel X400 sludge remover and run the system for about 3 hours and then re-flushed. After adding Sentinal X100 inhibitor I have found that when the CH is running (not the HW) there seems to be a surging water noise which is making the pump make a whirling noise with the sound of water being surged also. The system has been throughly bled but this problem still exists. The CH has only just been turned on again (for the onset of winter) so was wondering if this problem will just sort itself out when the system calms down to it's normal operating cycle.
Can anyone out there advise?

suffolklad · 4 Oct 2006

did you bleed rads with the boiler off ? pump not running. sounds like air being pushed through pump

wilhelm · 4 Oct 2006

pump right way around?
you never know.

Agile · 4 Oct 2006

"""followed the correct procedures i.e drained system throughly, flushed out all the rubbish and added Sentinel X400 sludge remover and run the system for about 3 hours and then re-flushed"""

How can you say that you followed any correct procedure when the X400 should be left in the system for 3-4 WEEKS not HOURS ?

Tony

wilhelm · 4 Oct 2006

tony.....lighten up chap. youre p£ssin me off.

pgatsky · 5 Oct 2006

Thanks for all your reply's.

1. Yes I did bleed all the rads more than once, one time with the boiler running and second more recently without the boiler running.

2. The pump is the same way round that the original was installed. I just replaced the faulty original after years of unconditional service.

3. As for the X400. I know it says on the tub that 3-4 weeks for a badly sludged up system but it also states a minimum of 2 hours for a less blocked up system which is what I reckon mine might have been.

Do you reckon I should have ignored the instructions and let the X400 run round the system for longer i.e 3-4 weeks. Would you therefore let the X400 run round the system without inhibitor being present?

One thought that recently sprang to mind was the fact that when I was cleaning out the F&E tank in loft, apart from there being a couple of cm's of sludge at the bottom, the air vent loop from the boiler was sitting right into the water itself. Is this right? As when I filled system back up I put a makeshift lid onto the tank and allowed the end of the pipe (air vent) to not go into the water.

ChrisR · 5 Oct 2006

If you didn't particularly have a sludge problem bofroe then what you did was ok.

No the vent pipe shouldn't be in the water.

It's just possible that the system's sucking air down the vent. Hold a tumbler of water under it while the pump starts, to see if it gets sucked up.
If that's OK and there's no water coming out of the vent pipe then leave it for longer - how long since you did it?

pgatsky · 5 Oct 2006

Thanks for that Chris R

When you say how long since I did it do you mean how long since I installed the new pump?

I will try that method of using the tumbler around the vent pipe later hopefully.

When you say leave it for longer are you talking about the system generally? To see if it just stabilises?

doitall · 5 Oct 2006

When you say the same as the old pump, was that the same orientation or the same as the arrow on the body.

Nige F · 5 Oct 2006

just to stir y`all for a change

I`m with agile........if there`s a sediment in the bottom. of the F+E....then it must be sludged. I`d leave it in as long as poss..and apply a vibrator to .........the rads

pgatsky · 6 Oct 2006

Thanks for reply's.

The pump I fitted was exactly the same model as the last one (Grundfos UPS 15-50) and I placed it in exactly the same position. Saying that, I haven't checked the orientation of the arrow if there is one just to see if it's different to the original.

At the risk of sounding unprofessional what is a vibrator to the rads?

Cheers

doitall · 6 Oct 2006

The pump may well be the same, but just as I always do, the installer may have spun the head so the electrics are on the top.

There is an arrow on the body.

pgatsky · 6 Oct 2006

Thanks doitall.

What would the other symptoms be if the pump was the other way round?

doitall · 6 Oct 2006

That would depend on the boiler and how its all connected up.

Air can get trap in high spots, between the water trapped in the dips, which is another reason for not using plastic, every time it dips down you get a potential air trap when you drain down.

Hold a glass of water under the vent pipe, get someone to turn the pump on and see if the water gets sucked out the glass.

pgatsky · 6 Oct 2006

Thanks doitall.

I take it then that if the water does get sucked out of the glass it could indicate that the pump's orientation is all round the wrong way?

Furthermore, I would have thought that if the pump was the wrong way round wouldn't the CH and HW not be working at all?

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Surging noise when CH runs!

wilhelm

wilhelm

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