Hot water flowing from vent pipe into loft tank

[BlueLoo]

Yes, I think you do

Interesting reply, don't disagree, but would you not look at cleaning the system as a whole rather than one spot?

That being so, would not powerflushing not be a better and more holistic and, less intrusive exercise?

Or is powerflushing a load of hocus pocus as thought by others pros on other forums?

And if not powerflushing, then what do you suggest for the rest of the system?

 

[fixitflav]

Interesting reply, don't disagree, but would you not look at cleaning the system as a whole rather than one spot?

That being so, would not powerflushing not be a better and more holistic and, less intrusive exercise?

Or is powerflushing a load of hocus pocus as thought by others pros on other forums?

And if not powerflushing, then what do you suggest for the rest of the system?

If OP wants to do my suggested mods (highly recommended!) the pipework must be cut out and cleaned at same time.
I'd guess he'd prefer a quick fix this time of year, in which case Sentinel X400 might do the job, and do anything more major in the spring.
I don't know much about powerflushing, but I believe it's not a popular as it used to be.

I had an overpumping problem a few years back. I had changed the pump which was noisy, and ran the new one at max, same as the old one. When I saw the overpumping, I checked the Magnaclean and it had a lot of brown sludge, rather than the usual black magnetic stuff. Dismantled the pipework in the feed/vent area and cleaned out some muck. Turned the pump down to min, and everything's been fine since. When I looked into the old pump the inside of the impeller was completely blocked, so performance down, why it needed max setting for the heating to work OK.
There's probably still some muck in the rads but it doesn't do any harm, and at my time of life I'm not going to bother doing anything!

 

[BlueLoo]

If OP wants to do my suggested mods (highly recommended!) the pipework must be cut out and cleaned at same time.
I'd guess he'd prefer a quick fix this time of year, in which Sentinel X400 might do the job, and do anything more major in the spring.
I don't know much about powerflushing, but I believe it's not a popular as it used to be.

I has an overpumping problem a few years back. I had changed the pump which was noisy, and ran the new one at max, same as the old one. When I saw the overpumping, I checked the Magnaclean and it had a lot of brown sludge, rather than the usual black magnetic stuff. Dismantled the pipework in the feed/vent area and cleaned out some muck. Turned the pump down to min, and everything's been fine since. When I looked into the old pump the inside of the impeller was completely blocked, so performance down, why it needed max setting for the heating to work OK.
There's probably still some muck in the rads but it doesn't do any harm, and at my time of life I'm not going to bother doing anything!

Here's a vid by Sentinel.

Interesting.

Here's another product sentinel do:
https://www.sentinelprotects.com/uk/products/sentinel-deposit-remover

Looks promising for the OP's situation

I would be doing the cleaning my own way and each to their own i suppose.

It's bugging me that given the bazzilion CH systems in use, cleaning the buggers isn't clear.
This thread is suggesting you can't, hence the chop-it-out approach. I look at that and think "what about the rest of it?" Does this mean these chemicals are snake oil?

I dunno.

I'd be cutting out as a last resort.
Perhaps an email to sentinel describing the problem may get a good response from thier tech department. Worth a go imho.

 

[fixitflav]

Another thought - maybe it's just the 300mm vent height being insufficient, if so it would be easy to extend that without doing any draindown etc. It needs doing anyway IMO.

 

[denso13]

I'd be cutting out as a last resort.

No, as a first resort. We are now ten pages in to what is a very, very common problem. Cut it out and replace, then go from there.

 

[BlueLoo]

No, as a first resort. We are now ten pages in to what is a very, very common problem. Cut it out and replace, then go from there.

And then fill the system up again, new additives, times, etc, and it still runs like **** because the ABV is set wrong, the pump is on max and the radiators are sludged up?

Right.

You plumbers need to no be so quick to cut stuff out.

Unless you are saying that the whole cleaning industry is an utter sham?

That couldn't be true, could it?

 

[denso13]

Unless you are saying that the whole cleaning industry is an utter sham?

No, but why spend a full day power flushing, plus chemicals, for something that may not be required?

It's a step by step approach, do the most obvious problem first, a few hours would sort that.

 

[BlueLoo]

No, but why spend a full day power flushing, plus chemicals, for something that may not be required?

It's a step by step approach, do the most obvious problem first, a few hours would sort that.

Right, don't disagree. Both solutions are ok imho. Just depends on what you want.
I like to do it as good as i can from the start. Cleaning won't make it worse, could clear the issue, will clean the rest if the system and eliminate need for cutting. Even if you do cut, you will still clean, no?

Anyway, many ways to skin this cat.

I like the exploration of the problems presented

 

[BlueLoo]

It will.

Look at the layout.

The pump valve is directly down stream of the blockage (apparently).

1. Shut down system.
2. Drain.
3. Remove pump
4. Rod Pipe upstream.
5. Shut valve.
6. Place bucket under valve
7. Turn on water.
8. Open valve
9. Catch crap in bucket.
10. Turn off valve
11. Fit pump back,vetc, etc.

Short term solution done. No cutting.
Shove in Sentinel **** buster. Rinse, refill. Enjoy hot rooms until summer refurb when the qualified plumbers who actually attended college are available.

It that such a bad solution?

 

[Dereekoo]

Cut out/unscrewed the following pipework several months ago (hence all those soldered joints) cos of over pumping issues and cleaned out best I could with wire and flushing. Put back in service and over pumping reduced, none on speed 1, bit on speed 2, more on speed 3. Also installed Magnaclean and flushed with Sentinel. Have cleaned Magnaclean 3 times since (full of carp) did another clean today , now no over pumping on any speed even with all radiators closed off. Consider my problem is now sorted

 

[fixitflav]

Cut out/unscrewed the following pipework several months ago (hence all those soldered joints) cos of over pumping issues and cleaned out best I could with wire and flushing. Put back in service and over pumping reduced, none on speed 1, bit on speed 2, more on speed 3. Also installed Magnaclean and flushed with Sentinel. Have cleaned Magnaclean 3 times since (full of carp) did another clean today , now no over pumping on any speed even with all radiators closed off. Consider my problem is now sorted
View attachment 254764

I still think your cold feed should be up-and-under, and there's plenty of room to do it that way.

 

[Dereekoo]

I still think your cold feed should be up-and-under, and there's plenty of room to do it that way.

I agree but this was the way 25 years ago, and I don't think they do air separators anymore due to blockages( would you believe)

 

[DP]

I still think your cold feed should be up-and-under, and there's plenty of room to do it that way.

It is good to have and correct to do that but will not cure the pump over issue.

 

[wardr77]

Just to update, as recommended on this thread, put 2 litres of X400 in the system today (19 radiators in house) put this in via the magnetic filter which I understand is an acceptable way of doing this. Will leave this in until the new year and see what happens, but assume I will need to replace the junction. I wont lie there is a temptation there to clear out the blockage by removing the pump and give it a poke, but concerned that I will dislodge a large chunk of magnetite that will cause bigger problems somewhere else! Thanks all again

 

[fixitflav]

but concerned that I will dislodge a large chunk of magnetite that will cause bigger problems somewhere else

That shouldn't be a problem. Following BlueLoo's #150, the muck will be flushed out from where the pump goes. If you have a helper you could crack the cold fill valve before rodding, to give a flow and make sure the muck doesn't drop into the pipe before the tee.
You're fortunate with your layout in that you can remove the pump to rod, often the open vent and cold feed are remote from the pump, so more dismantling, or cutting and resoldering, are required.
Good luck anyway!