Slishing sound from central heating?

The_Governor

I couldn't see a topic like this one, so thought a new post was best.

It's hard to describe in text, but when our heating is on, just after the boiler switches off and the pump over-runs there is a sloshing/glugging sound from what sounds like the pipes just above the boiler.

Almost like the sound of puring water into a fish-tank type noise.

I've built up a theory that it happens most when it is only heating the water.

Also, one of the radiators (the one closest to the pump in the airing cupboard) needs bleeding every couple fo weeks as it fills with air.

My guess is that when the water only is heated, the pump finds it easier to suck air through the header tank rather than around our fairly large system.

Based on that, I'm thinking of raising the header tank to increase the head of water above, but wanted to get some advice before I do anything.

I should also mention, if I put the pump on speed 2 the problem goes away, but that speed isn't sufficient to heat the rads, again due to the size of the system.



The system is an Ultrawarm 60FF, there are 17 standard rads (no thermostatic valves) in total, with a tank in the airing cupboard, so I think a conventional one?



P.S. I did post this on a DIY forum earlier today and caught a load of flack for saying my system was big so please don't think I'm bigging myself up, I'm just trying to give as much info as poss.

Canucklehead

Hi

They can be a bit touchy over there,usually because of a lack of info.I would agree about the blockage,along with a generally dirty system (assuming the system has been working quietly previously?) Post a photo of the pump and pipework ?

Corgi Guy.

The_Governor

Thanks CG, in actual fact it's always been a bit noisy since we moved in a few years ago, but it's only now I've thought beggar it, and want to get it sorted.

You think maybe a blockage somewhere in the system, worth flushing it do you think?

I'll take some pics too in daylight tomorrow

Canucklehead

Hi

If it's always been a bit noisy then it might be a basic system problem and not so easy to solve.Look forward to a photo.

Corgi Guy.

The_Governor

Photo attached

Canucklehead

Hi

See here ...http://www.glow-wormorders.co.uk/manuals/pdf/Boilers/Ultimate60FF.pdf
Page 9 3.3 Bypass and page 10 diag 3.2.

Unless the bypass (with the red handled valve which has the cyl stat cable on it) goes to a rad/towel rail in the bathroom you don't need it, turn the valve off.
As I mentioned the system has a basic problem ie; not piped as per the manual.The vent is off the return not the flow.
The cold feed is prone to blocking and is also on the return (although it's as per instructions and goes 'up and under')
To establish if you have a blocked cold feed you will need to drain water from the system. If the expansion tank does not empty it's blocked.

Might be best to get some one in if you are not very DIY

Corgi Guy.

plumb1_2

Yes , the sysytem has been piped up wrong, not stuck to the good old 3T rule, 1st tee is always the vent. And the cold feed will always attrack any sludge to biuld up in it and block it.

espresso

plumb1 wrote: »

Yes , the sysytem has been piped up wrong, not stuck to the good old 3T rule, 1st tee is always the vent.

Are you guys sure? The picture detail is not great but could it not be plumbed as per requirements? e.g.

The_Governor

Wow, guys can i just say thanks to you all for the extra information.

espresso - would it help if I took a closer pic (I was trying to show as much as poss in the first one)?

CG - I'm sure this is a dumb question, but I'll ask anyway, how would I know if that bypass valve is connected to a rad without pulling up the floor? [EDIT] As far as I tell, it comes off the pipe below and then goes over to just above the pump, no other connections at all... it is warm to the touch though.

Could I switch it off and see what happens, or will I cause a bigger problem if i do (like my boiler exploding)!

As you'll have no doubt guessed I'm no heating engineer, I'm not a cretin with my hands but would only do it myself if I knew where I was going with it.

I'm not against getting someone in (when I can afford it ! ) but I'd like to be clued up enough to know if I get someone trying to pull a fast one!

I just gave the suspected bypass valve a (ginger!) wiggle, it sounded a bit like there was stuff in there as I turned the handle, sort of like as it might sound with sludge in there... is it possible the bypass is blocked and that could cause it?

The_Governor

Just thought I'd do a closer one anyway in case it helps...

Canucklehead

Hi

That's clearer
I am corrected. The cold feed /open vent are on the flow.If I had piped it it would look more like the manual diagram, but that's just me.It could be argued it's ok as it is ,but I don't/won't get into that.
You do not need the bypass, it literally is a short circuit and goes nowhere else. It will not solve your problem but will improve circulation to the h/w, c/h.Turn it off as you would a tap.
Another detail,that won't solve your noise, I don't see a single clip on any pipe.

Corgi Guy.