Cold water discharge from vent on f&e!

[Pooly89]

Hi guys,

I have a little problem at a customers property that really I just want confirmation that I am going down the right route(don't want to keep having to go back & cost her an arm & a leg lol). I have attached a picture of the pipe work set up to help illustrate my point.

Basically its a aged system I was called out to a noisey pump, the pump was an old myson that sounded like it was gonna take off so, naturally I changed the pump for a grunfoss 15-50 (by the way I did notice discharging water before replacing the pump). When filling up the system after replacing the pump I wanted to check that water wasn't discharging from the vent on the f&e when the pump was just running cold water to obviously try and rule out an overheat issue. water was found to be discharging when cold from the f&e vent pipe so then my next port of call was to the pipework and this is what I saw.

So obviously I am looking at the cold feed and vent set up and thinking the cold feed should be on the return side of the heating system or at least not anywhere near as close as it is to the vent as it is in the pic. I am I right in thinking this?, if not any ideas what else could cause discharge into f&e even when COLD? (pump set a MIN by the way same as previous pump).

Cheers

 

[diamondgas]

Poorly configured pipework is your isue I'd say! Why installers think air will go horizontally amuses me

Cheapest option would be to combine the feed and vent if the installed appliance will allow, otherwise an expensive reconfig of pipes to guarantee solving the problem .... IMHO

 

[Pooly89]

Well that's what I thought but apparently this is a acceptable way to pipe the system :mad2:

I have found that other people have had similar problems and it was found to be a blockage between the feed and vent pipes due to rust, sound plausible?

 

[Rickster123]

Sounds very plausible pooly. As suggested already if you have the pump on speed 3 I would turn that down and if that doesn't sort it have a look for a partial blockage or restriction.

Ps, the word discharge makes me heave!

 

[Simon F]

the feed and vent should be no more than 150mm apart, so as to create a neutral point.
I should cut that section of pipe to have a look for a blockage. or use a magnet on the pipe, if it pulls to the pipe then there is metallic buildup.

 

[Pooly89]

thanks APPlumb I had already turned the pump to 1 and it's still DISCHARGING! haha sounds like you've had some nasty problems with things discharging in the past mate, maybe try cleaner women! haha

Simon F, cheer I will try the magnet option first (I hadn't thought of that) first as cutting pipe means draining down again.

 

[AWheating]

sounds very plausible pooly. As suggested already if you have the pump on speed 3 i would turn that down and if that doesn't sort it have a look for a partial blockage or restriction.

Ps, the word discharge makes me heave!

discharge, discharge, discharge!!!

 

[dancinplumba]

have you got the pump the right way round ?

 

[GrahamM]

have you got the pump the right way round ?

And don't assume the old one was on the correct way either.

 

[Pooly89]

yeh i'm sure I've put the pump in the right way round its flowing towards (vertically) the 3port valve on the system if it was the other way round it wouldn't do much for the circulation

 

[dancinplumba]

ok

 

[SafeGasInstall]

Go back , drain down and cut out the cold feed and the vent .
do as dimond says , but keep it in 22
if there is blockage cut and replace
inhibitour in on thw way out

 

[Pooly89]

Go back , drain down and cut out the cold feed and the vent .
do as dimond says , but keep it in 22
if there is blockage cut and replace
inhibitour in on thw way out

I don't know what Dimond means by a combined feed & expansion pipe to be honest as I've never seen or had to put one in. I was intending to cut and replace any sections of blocked pipework, when you say keep it in 22 do you mean up size the cold feed which is 15? obviously I was going to leave as is and just replace any blocked sections.

 

[GasmanxxxR1]

You can run a 22mm pipe as a combined open vent and cold feed or more easily tee the cold feed directly into the open vent higher up.

No the cold feed should not be on the return, as stated before Max of 150mm away from open vent.

Ps theres nothing wrong with the pipework layout as it is. Just a blockage in the cold feed

 

[Pooly89]

Right guys what I have done today to try and narrow this problem down with the spare few minutes i've had is to touch a magnet on the pipe around the cold feed and vent pipework where they meet in the pic. Unsurprisingly the magnet seem to pull toward the section of pipework between the floor and the pump but seemed to really pull towards the T's and the section of pipe in between them I think this maybe where the blockage is I am calling back at another time when I have more time to drain down and remove this section of pipework.

 

[diamondgas]

I don't know what Dimond means by a combined feed & expansion pipe to be honest as I've never seen or had to put one in. I was intending to cut and replace any sections of blocked pipework, when you say keep it in 22 do you mean up size the cold feed which is 15? obviously I was going to leave as is and just replace any blocked sections.

General rule of thumb regards combining f&v, boiler has to have a pump overrun and o/heat cutoff device fitted! You could utilize the existing open vent pipe as the combined pipe, do away with the 15mm feed and increase the tank connection in the expansion tank to 22mm to accommodate the combined pipe! No need for the open vent loop over the top! HOWEVER the boiler must be as said AND it's best to consult the mi's or contact the manufacturer if you're not sure!!

The issue i have with a vent taken off horizontally is the removal of air in the system. It'll trap in the top of the radiators obviously but will never 'vent' naturally!

 

[Pooly89]

Right guys, It seems to have been rectified by removing the blocked pipe work and replacing with new. Cold feed pipe had hardly any space for water to pass through surprised the system worked at all to be honest. thanks for all your advise will definitely come to the site in the future if I need help or can offer help to anyone. Nice one guys, nightmare over.

 

[Simon F]

:smile5:..glad to hear its all sorted...:8: