Hot water flowing from vent pipe into loft tank

[Gasguru]

Reviews written by customers mean absolutely nothing...what do most homeowners know about gas/heating regulations? A Worcester approved installer means you've attended a days selling course...nothing about competence.
Post some pics showing the arrow on the pump back casing, the arrows on the zone valves (to see what direction they expect the flow), and the boiler pipework.
What's the boiler make and model...that will give you the flow pipe from the boiler and you'll easily tell whether the pumps been installed back to front.

 

[Exedon]

No problem what speed is pump set on ? As indicated by lights on it?

 

[DiyNutJob]

If the flow direction is correct, are you quite sure you have a problem? A little venting into the vent pipe is normal. What makes you believe you have a problem? Also, what is the rough length of the vent pipe? My guess it's a couple of meters and that's more than good enough.

 

[Exedon]

If the flow direction is correct, are you quite sure you have a problem? A little venting into the vent pipe is normal. What makes you believe you have a problem? Also, what is the rough length of the vent pipe? My guess it's a couple of meters and that's more than good enough.

Venting through open vent is not normal!
Ever time it happens water gets re oxygenated and back into system = corrosion!

 

[wardr77]

The vent pipe is definitely more than 2 metres, going from ground floor into loft space. Speed setting is on 1.when heating on, hot water is going into f&e tank I've been up there watching it not a lot at setting 1 but enough for the water in the tank to be hot. Now that I've confirmed the flow direction, would the combining of the vent and feed cure the problem after all?

 

[wardr77]

Or do I need to get the feed / vent junction cut out and replaced with new, theres definitely some magnetic attraction there.

 

[BlueLoo]

Sorry guys I've been a ****, could have sworn the arrow on pump was pointing towards vent, just gone in there again with torch and glasses and arrow is towards ABV ie flowing away from vent. Sorry about that, feel stupid!

That would be correct i think.

I can't figure out where your zone feeds are. It looks like you have two supplies after the pump, but one is 22mm and one is 15?

Dunno. The ABV is returning to somewhere on the downstairs return ir seems.

The feeds seem odd. Hard to say.

I think like i said before, your system is chock full of gunk.

If you can, drain down, remove rads, flush, refit, fill system with cleaner, leave for a week (if allowed), drain, fill with inhibitors. Set ABV according to normal procedure. Set pump speed to 1, Fixed speed (NOT pp/cv).

Draw system out, check configuration.

Should be ok after that.
Or get a plumber in to do it.
Certainly, take heed of the pros comments here above all. They know best. Us DIYers are just that.

Best of luck.

 

[wardr77]

Yes the ABV pipe connects up with the return pipe and goes into back of boiler

Dont think the overpump is normal, can actually hear it standing under the loft hatch. Steam coming off the water in the f&e tank which cant be good for the loft space let alone anything else I would have thought

Thanks again for all your replies

 

[Dereekoo]

Pump needs to be after the vent pipe and feed other wise its putting positive head on vent pipe and hence overflowing so no pipework needs changing

It's totally normal. Otherwise the inhibitor put in the expansion tank would never get into the system.

Perhaps thats why you put the inhibitor in at the same time when you are filling the system (usually at initial commissioning or just after you have drained the system of Sentinel x800 or similar)

 

[DiyNutJob]

Perhaps thats why you put the inhibitor in at the same time when you are filling the system

I don't. I put it in the ground floor radiator and it ends up in the loft tank above the second floor - 3 storeys up. First hand research will bring you knowledge. Otherwise you are easily panicked by random things people say.

 

[Gasguru]

There are very strict regulations regarding heating systems to protect the occupier from serious harm.
Pumping towards a close coupled feed & vent is in no way normal, a completely unrestricted path from boiler to vent is ALWAYS required.
Before any discussion on pump speeds, bypass settings or else the basic configuration must be checked for safety.
Over the years us in the trade have attended many systems apparently working (or have worked) that are fundamentally unsafe and non compliant....the owners oblivious to the danger.

 

[DP]

I'll suggest that the hydraulic resistance of your circuit is such that the new pump is just finding the path of least resistance without the neutral point being in the correct place to hold it back.

A pump will either work or not. If it was spinning, you were likely getting a normal head. Changing the pump wouldn't fix the reason for cold rads.

Was the system powerflushed when the filter and pump were replaced?
If not, then i suggest you take the rads off and hose them through in the garden. Your system may still be sludged up.

If your system was cleaned (I'd still prefer to clean the rads as above), then maybe the new pump is just too good that its now pumping over, where your other wasn't.

If you are handy enough, perhaps just replumb the FE pipe to where it should be, and clean out the rads. Your system will work much better.

It's a similar situation i had.

Best of luck. (Read my sig).

What a load of inane rambling.
The pumpover is due to incorrect plumbing or blockage.

 

[DiyNutJob]

The pumpover is due to incorrect plumbing or blockage.

There's no proof of the over pump. Proof is easily achieved with a picture of vented water falling into tank.

The physics would not allow an over pump given the huge column of water inside the vent pipe. I would expect some intermittent overflows when valves shut off. I would expect some dribbles.

 

[BlueLoo]

There are very strict regulations regarding heating systems to protect the occupier from serious harm.
Pumping towards a close coupled feed & vent is in no way normal, a completely unrestricted path from boiler to vent is ALWAYS required.
Before any discussion on pump speeds, bypass settings or else the basic configuration must be checked for safety.
Over the years us in the trade have attended many systems apparently working (or have worked) that are fundamentally unsafe and non compliant....the owners oblivious to the danger.

If i may ask a question,
Is it normal in your experience to find heating systems correctly configured?

How much trouble is due to poor design and installation vs equipment failure?

Reading this board, and my own observations would suggest that well designed systems are a rarity.

I know mods, changes, etc can may a good system bad but still,

 

[wardr77]

Sorry chaps, just to clarify,I did make an error which I explained earlier today. The pump direction is away from vent and feed and not towards it as I first suggested, sorry for the confusion caused. So it appears flow direction is correct, it's just the case of what is now causing the overpump, which could be a blockage of some sort...thanks again all