Open Vented System - Banging and Noisy

[weggy1985]

Hi,

I have an Open Vented System with a few issues that are worrying me.

Firstly when I turn off my hot water I get a loud banging noise, I understand this could be to do with the water slowing/stop its direction. If this is the case is there anything I can do about it? It sounds bloody terrible I've tried turning down the pump speed next to the cylinder.

Secondly I can hear a noise when the heating and hot water is off coming from all radiators. I believe its coming from the water cylinder which appears to be heating the water when the hot water is off. I think this is due to the cylinder thermostat which is at 60 (correct me if im wrong please). But I don't think the cylinder should be making such a loud noise. Is there anything that is likely to be causing that?

I'm close to getting my system serviced but I really don't want to cause it bloody expensive

Any help would be appreciated

Many Thanks,

Elliott

 

[Groovejet]

No pump over run
System could be scaled up
Immersion could be left on causing boiling/kettling noice. If not your programmer couls be faulty and need replacing or your wiring incorrect.
Thanks

 

[slapper]

The noise your getting when you turn the hot tap off, after running off some hot water, will be water hammer caused by the ballvalve in the bigger tank that feeds your hot water cylinder. Get that replaced, and that should sort it.

Don't know whats causing the other noise, but don't think its anything to with pump overrun, otherwise boiler would go to o/heat and lock out

 

[Nige F]

Hi,


Firstly when I turn off my hot water I get a loud banging noise,
Secondly I can hear a noise when the heating and hot water is off coming from all radiators.
Any help would be appreciated

Many Thanks,

Elliott

First one - do you mean you switch water off @ programmer ? Second one - can you check if the pump is running though it shouldn`t be ? Can you post some pics , and where are you in Sx.

 

[weggy1985]

Hi, thanks for the responses. I'm at work at the moment so I'll try and post pictures later tonight (including expansion tank condition) with some more info.

First, when I shut the CH off from the programmer the bang happens and second the pump isnt on while the cylinder is making noise. I'm based in Horsham.

Many Thanks,

Elliott

 

[weggy1985]

Hi,

In the below link is an album, you should be able to see some pictures I've taken of my setup and its current state:
//www.diynot.com/network/weggy1985/albums/23442

I've take some random ones just incase you notice anything odd. But the obvious one is the stuff in the expansion tank. It wasn't that long ago (nearly a year) that I flushed the system and added a new inhibitor.

Cheers,

EL

 

[Groovejet]

Yea, first thing you should tie the ball cock up with some string to stop water from filling header tank up and get a bucket and small container and fish out all the water and rubbish from the tank.

Then i would tend to add a cleaning chemical to the same header(small one) as if you drain heating then refill the water there's the possibility of dragging all the rubbish into some difficult area, where it'll get stuck.

The good side is you said 15mm branch off to rads? SO thats alot better than 10 or 8mm pipe as that would of caused you more blockage problems.

After the chemical has done its job , from 1 day to a week(read instructions ) then you can tie up ball cock again or turn stop cock off and drain the heating.
Open all the bleeds on radiators and wait for hose to stop.

You can flush the heating through a little bit by putting water back on by releasing ball cock and leave it to drain out hose /drain valve.
Remember to close all the bleeds on the radiators then fill up , adding a inhibitor chemical to the header tank (small tank) bleeding the air out of the radiators till there full.
Turn boiler back on, and go around again to get all remaining air out.

Remember ? When you add a inhiitor or cleanser, don't pour into a full header tank of water , it wont circulate and will eventually turn to jelly. Drain off some water then add it, this way it gets to circulate correctly

p.s - there a drain off in your picture of cylinder but this isn't for the heating so don t drain this unless you want the hot water to drain!!
- find one either on top of boiler or on a radiator or such like...ther'll be one somewhere. If not choose the easily accessible radiator and remove it, then connecting hose onto pipe and closing other rad valve end, otherwise you'll be swimming in your kitchen!!

 

[weggy1985]

I've drained my system before, so doing it again shouldn't be a problem. I wonder if I didn't use enough inhibitor (I used 1 litre). Although with only 7 radiators I'd expect 1 litre to be enough.

I was going to use Sentinel X400 System Restorer to clean the system.

Then use Sentinel X100 Inhibitor to protect it, would you agree with this?

Do you think the dirty system is the cause of the banging noise? I wouldn't of expected that.

 

[Nige F]

As to the bang when the programmer is switched - listen ( with ear to a screwdriver handle and blade on valve ) to the 3 way blue top valve above the pump - this may be the cause of the noise from water hammer

 

[weggy1985]

Oddly the banging isnt happening right now so I cant listen hehe But when it does I shall.

HOWEVER! Something I've just noticed and randomly discovered after watching an indirectly related video is...

We have this odd issue where BOTH our hot water and heating must be both on in order for out heating to work. Now I've just seen a video which mentioned your heating can stop working and sometimes the broken 3 way valve can we the reason. A hot fix is to switch the value to normal BUT if you do this you have to have both heating and hot water on at the same time.

SO I THOUGHT, wait a minute I should check ours to see if it is on manual. Guess what, it is! Now is there something I could be missing here, should it be on manual for other reasons I don't know or could it be on manual as the 3 way value is actually broken and the previous owners bodged a fix?

 

[Nige F]

Does sound suspiciously like a dodgy 3 way valve

 

[Scarum]

If the actuator on the 3-port valve has always been on manual over-ride then the hot water cylinder has been heating up rather well for some time!

It could be the cause for the noises. What model 3-port valve is it? Can you remove the actuator from the valve body? Some one you can without a semi-drain down.

 

[weggy1985]

It appears to be a "Horstmann Z322 3-Port Motorised Valve"

http://www.horstmann.co.uk/products.../motorised-valves-actuators/zoneplus-z-series

Screwfix sell these units:
http://www.screwfix.com/p/horstmann-z322-3-port-motorised-valve/27172

 

[weggy1985]

If I try switching it to Auto for a bit can I cause any damage?

I'd like to see if the switch was simply mistakenly moved or if the valve is actually broken.

 

[Scarum]

No- give it a go.