Adding Plumb 7 to open system

LittleGarry · 30-01-2021 3:52pm #1

Hi Folks,
I have an open vented heating system (oil & solid fuel) with header tank. There is a small leak - circa 700ml per day based on water loss from header - which I have narrowed down to an 8ft section of underground (solid concrete floor) pipe between two rooms. I really don't want to get the kango hammer out as one of the rooms is a newly tiled / fitted bathroom!
I was going to have a go at a leak sealant. Reading posts here and in other places it seems Plumb 7 comes fairly well recommended. I am just wondering if I would need to drain down the system in order to put the plumb 7 in or can I just take a few litres of water out of the header tank, pour the sealer in there and let nature take its course? I have 12 averaged sized double rads and was going to go with two bottles - or would this be overkill?
Thanks for your help!

K.Flyer · 30-01-2021 4:16pm

You really need to get the treatment down into the system as best as possible.
If you could drain a few gallons out of the system then pour the treatment in via the header you have a better chance of it getting the job done.
I would suggest to turn off all upper floor radiators, try empty out the system at least as far as the cylinder coil, add your treatment, two well shaken cans would be plenty, refill the system at the header, leave the upstairs radiators off and any downstairs ones that you don't need and are not running off the leaking pipework, turn on your central heating system and let it run for at least a few hours to allow the treatment to concentrate on the affected area, monitor water level in the header.
By doing it this way you are getting the maximum strength of the treatment into the affected area and not diluting it by running it around parts of the system that it doesn't need to go through.
After at least a few hours you can turn back on radiators that are required, but the longer you can leave it the better.
Also consider using a product called OxiPic. To be honest I think it's a better product. Same instructions as above, but shake the bottle well and using gloves open the bottle over or in the header tank as it's very messy stuff.

LittleGarry · 30-01-2021 4:26pm

K.Flyer wrote: »

You really need to get the treatment down into the system as best as possible.
If you could drain a few gallons out of the system then pour the treatment in via the header you have a better chance of it getting the job done.
I would suggest to turn off all upper floor radiators, try empty out the system at least as far as the cylinder coil, add your treatment, two well shaken cans would be plenty, refill the system at the header, leave the upstairs radiators off and any downstairs ones that you don't need and are not running off the leaking pipework, turn on your central heating system and let it run for at least a few hours to allow the treatment to concentrate on the affected area, monitor water level in the header.
By doing it this way you are getting the maximum strength of the treatment into the affected area and not diluting it by running it around parts of the system that it doesn't need to go through.
After at least a few hours you can turn back on radiators that are required, but the longer you can leave it the better.
Also consider using a product called OxiPic. To be honest I think it's a better product. Same instructions as above, but shake the bottle well and using gloves open the bottle over or in the header tank as it's very messy stuff.

Thanks for your help K. Flyer, much appreciated.
It is a bungalow so this may simplify things slightly. I have spent the last few minutes searching the hotpress for some type of drain fitting that a hose could be connected to - other than the one at the base of the hot water cylinder - I am seeing nothing on any of the heating pipes. Could there be a drain point located anywhere else in your experience - beside the oil boiler perhaps which is outside? Thanks Again!

Dtp1979 · 30-01-2021 4:44pm

LittleGarry wrote: »

Thanks for your help K. Flyer, much appreciated.
It is a bungalow so this may simplify things slightly. I have spent the last few minutes searching the hotpress for some type of drain fitting that a hose could be connected to - other than the one at the base of the hot water cylinder - I am seeing nothing on any of the heating pipes. Could there be a drain point located anywhere else in your experience - beside the oil boiler perhaps which is outside? Thanks Again!

Add it to a radiator if they are the newer type (last 10 years) with the removable 1/2” vent. Use 1/2” elbow and funnel. How many radiators do you have? I’d be more a fan of plumb 7 than oxypic myself, but each to their own

K.Flyer · 30-01-2021 4:50pm

LittleGarry wrote: »

Thanks for your help K. Flyer, much appreciated.
It is a bungalow so this may simplify things slightly. I have spent the last few minutes searching the hotpress for some type of drain fitting that a hose could be connected to - other than the one at the base of the hot water cylinder - I am seeing nothing on any of the heating pipes. Could there be a drain point located anywhere else in your experience - beside the oil boiler perhaps which is outside? Thanks Again!

There should be a drain point at the boiler, but if not, find the smallest radiator, (bathroom?), remove it and drain from radiator valve.
Follow the instructions as last post, just turn off all unnecessary radiators and drain about 20 litres below the header, add treatment, then refill and run the system as per last post.

Dtp1979 · 30-01-2021 4:57pm

K.Flyer wrote: »

There should be a drain point at the boiler, but if not, find the smallest radiator, (bathroom?), remove it and drain from radiator valve.
Follow the instructions as last post, just turn off all unnecessary radiators and drain about 20 litres below the header, add treatment, then refill and run the system as per last post.

But how will he know which rads are unnecessary cause he doesn’t know where the leak is.

LittleGarry · 30-01-2021 4:57pm

Dtp1979 wrote: »

Add it to a radiator if they are the newer type (last 10 years) with the removable 1/2” vent. Use 1/2” elbow and funnel. How many radiators do you have? I’d be more a fan of plumb 7 than oxypic myself, but each to their own

Thanks for your response Dtp1979. The house is 13 years old. Image of both ends of one of the rads attached - there are 12 rads in total, all double walled units ranging from 3ft to 6ft in length.
I assume if I was to take this route I would isolate the rad from the system by closing off both valves, loosen the rad slightly at base to drain off a couple of litres of water from it and pour the product in through the top?

Dtp1979 · 30-01-2021 4:58pm

LittleGarry wrote: »

Thanks for your response Dtp1979. The house is 13 years old. Image of both ends of one of the rads attached - there are 12 rads in total, all double walled units ranging from 3ft to 6ft in length.
I assume if I was to take this route I would isolate the rad from the system by closing off both valves, loosen the rad slightly at base to drain off a couple of litres of water from it and pour the product in through the top?

Yes exactly. Add the chemical on the blank cap side and leave the bleed vent open. 2 bottles should do fine. No harm in 3 though

K.Flyer · 30-01-2021 5:11pm

Dtp1979 wrote: »

But how will he know which rads are unnecessary cause he doesn’t know where the leak is.

If he has identified the section where the leak is I would have thought that he could figure which rads are running off that section. By minimising rads to the affected area you get the stronger concentration of treatment into the leak.
In my first post I didn't know it was a bungalow, but I would still suggest to go through the header as it's less tricky for a DIYer than into the rad. Plus those rads are low water volume, he will do well to get two cans into it.

Dtp1979 · 30-01-2021 5:14pm

K.Flyer wrote: »

If he has identified the section where the leak is I would have thought that he could figure which rads are running off that section. By minimising rads to the affected area you get the stronger concentration of treatment into the leak.
In my first post I didn't know it was a bungalow.

Of course. I totally agree with you regarding upstairs rads. But unless he knows where the area is downstairs, snd seeing as this is a bungalow, I’d leave on all rads

LittleGarry · 30-01-2021 5:16pm

K.Flyer wrote: »

There should be a drain point at the boiler, but if not, find the smallest radiator, (bathroom?), remove it and drain from radiator valve.
Follow the instructions as last post, just turn off all unnecessary radiators and drain about 20 litres below the header, add treatment, then refill and run the system as per last post.

I had a look outside around the oil boiler, I am seeing nothing on the pipework on the right side of the boiler but there does look to be a (fairly well corroded) bolt on the left hand side right on the bottom of the boiler unit itself - this would hardly be it would it? It makes me nervous even looking at it to be honest - looks like if it opened it may never close again!!

LittleGarry · 30-01-2021 5:19pm

Dtp1979 wrote: »

Of course. I totally agree with you regarding upstairs rads. But unless he knows where the area is downstairs, snd seeing as this is a bungalow, I’d leave on all rads

I do have it narrowed down to about an 8ft section of pipework between two rads in the bedroom / en-suite...

K.Flyer · 30-01-2021 5:22pm

Dtp1979 wrote: »

Of course. I totally agree with you regarding upstairs rads. But unless he knows where the area is downstairs, snd seeing as this is a bungalow, I’d leave on all rads

In the original post he says he has identified the location to a section under concrete floor between two rooms, hence my suggestions.
Leave the radiators on in these two room and turn the rest off.

K.Flyer · 30-01-2021 5:25pm

LittleGarry wrote: »

I had a look outside around the oil boiler, I am seeing nothing on the pipework on the right side of the boiler but there does look to be a (fairly well corroded) bolt on the left hand side right on the bottom of the boiler unit itself - this would hardly be it would it? It makes me nervous even looking at it to be honest - looks like if it opened it may never close again!!

Don't touch the one on the left and I can't make out anything else on the right.
I think best to drain via a radiator, probably the bathroom one with a tiled floor.

Dtp1979 · 30-01-2021 6:28pm

K.Flyer wrote: »

In the original post he says he has identified the location to a section under concrete floor between two rooms, hence my suggestions.
Leave the radiators on in these two room and turn the rest off.

I missed that part. Yes I totally agree about not diluting the tec7 any more than it needs to be.
Out of intrest op, how did you identify the suspect area?

Also, the bottom of the boiler looks damp and it’s in bad need of a service if the oil hose is anything to go by

LittleGarry · 30-01-2021 6:43pm

Dtp1979 wrote: »

I missed that part. Yes I totally agree about not diluting the tec7 any more than it needs to be.
Out of intrest op, how did you identify the suspect area?

Also, the bottom of the boiler looks damp and it’s in bad need of a service if the oil hose is anything to go by

Yep, the boiler is on it's last legs - it's on the list to be changed out altogether to a more efficient one this summer hopefully - it went in when the house went up 13 years ago - in fairness it has been a couple of years since it was serviced!
The leak is causing paint to bubble off a wall behind one radiator (in bedroom) and also caused a few tiles (that were laid last year) to pop in the en-suite as the adhesive did not dry properly - this is what made me go looking initially.

When I dug down through the concrete the insulation around the pipe was very wet, and started to "seep" shortly after heating was turned on and pump kicked in. I therefore have a good idea that the leak is at a point between where I dug and the bubbling wall behind the radiator in the adjoining room about 8 ft away - my guess is it is directly under the radiator in the bedroom tbh but it is a guess and not worth taking a kango to unless I have no other option in my view. The water is then being adsorbed into the insulating and making its way under the en-suite I reckon. As I mentioned above it is small - about 600ml - 700ml per day based on water loss from the header tank so I am hoping the sealant will work.
Thanks again for your help!

Dtp1979 · 30-01-2021 8:47pm

Let’s us know how it goes snd don’t waste your money on anything other than plumb7 or oxypic, no matter what the guy behind the counter says!!

LittleGarry · 25-02-2021 3:28pm

Dtp1979 wrote: »

Let’s us know how it goes snd don’t waste your money on anything other than plumb7 or oxypic, no matter what the guy behind the counter says!!

Ok guys, just want to again say thanks for your help with this. Just wanted to give you an update - as much for your own amusement as anything else tbh!:)

This has taken a while as I have had what I can only describe as a linked comedy of errors going on since adding the Plumb 7 to the system 3 weeks ago now!

As suggested I took off the bathroom rad, drained about 30 - 40 litres of water from the system, reconnected the rad and added Plumb 7 in from the F&E tank (obviously empty at that point). Closed off all rads only the 3 in the leak area, refilled the F&E tank and ran the system for a few hours.

I had a look at the F&E tank water level and how much had been topped up (had left a slim plastic lunchbox under filler on ball valve) 24 hours later - there was a small drop - a fraction of the circa 700ml that was being lost in 24 hours before adding the chemical.

Then the fun began - it was still bugging me as to why any water should have been replenished into the F&E at all over that period 24 hour period!! I noticed the float ball was partially submerged as there was a small bit of water in it - took it off and changed it. The man handling of changing that seemed to cause a constant subsequent drip from the filler valve itself (14 yrs old) so I decided to change that too. In an effort to turn off the water to the F&E I turned the isolater valve located 6" from the feed into the tank - of course that than started seeping water out through the actual screw also as it most likely had seized over the years!! So changed both the isolator valve and the fill valve in the tank! Then I noticed that the system seemed to be pitching a small bit of water out through the overflow pipe - not every day but a couple of times a week..... After some subsequent research I discovered that the water was too high in the tank (within about 20mm of overflow when cold). Dropped the water level in the tank down so that the tank is now more or less 50% water and 50% air and it hasn't pitched or lost a single drop of water in the last 3 days!

I am very much hoping that I am done with this now - other than to put the tiles back down in the bathroom and repair and re-paint the water damaged wall:cool:

Adding Plumb 7 to open system

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