Suspected blocked feed t on heat only system

[diycooper]

I suspect I have a blocked feed T on the system. When hot water is heating up there s banging on pipes. The system recently had a drain down to replace a 3 port valve. I do not think the feed was isolated by gate valve or tank bunged and may have pulled sludge in on re fill.


Going to check it's not blocked at f n e end and clean that out. But failing that going to check the T if needed. .

It not quite in picture below but it located top left corner. It is a 22mm to 15mm compression T.

Question is. If I turn off gate valve located above the T. Can I just drain the water from below the T by cracking the nut on 3 port valve and catching.. To save a full drain fown ?

 

[terryplumb]

If there is an isolation valve on the feed from the loft tank, and it's above the Tee that you suspect may be blocked, close it and drain some water out the system from a low point.
If the isolation valve is a gate valve ( usually with a large ,red coloured ,wheel head) be aware that they are notorious for not fully closing ,and can snap internally if overtightened,and then don't open up either !

 

[diycooper]

If there is an isolation valve on the feed from the loft tank, and it's above the Tee that you suspect may be blocked, close it and drain some water out the system from a low point.
If the isolation valve is a gate valve ( usually with a large ,red coloured ,wheel head) be aware that they are notorious for not fully closing ,and can snap internally if overtightened,and then don't open up either !

Yes to be safe from snapping the valve

I suspect I have a blocked feed T on the system. When hot water is heating up there s banging on pipes. The system recently had a drain down to replace a 3 port valve. I do not think the feed was isolated by gate valve or tank bunged and may have pulled sludge in on re fill.


Going to check it's not blocked at f n e end and clean that out. But failing that going to check the T if needed. .

It not quite in picture below but it located top left corner. It is a 22mm to 15mm compression T.

Question is. If I turn off gate valve located above the T. Can I just drain the water from below the T by cracking the nut on 3 port valve and catching.. To save a full drain fown ?

Thanks. I'll get a new ball lever valve incase. Then may bung the f n e and remove valve first and see if it was faulty. I can then look down to the t.

 

[diycooper]

If there is an isolation valve on the feed from the loft tank, and it's above the Tee that you suspect may be blocked, close it and drain some water out the system from a low point.
If the isolation valve is a gate valve ( usually with a large ,red coloured ,wheel head) be aware that they are notorious for not fully closing ,and can snap internally if overtightened,and then don't open up either !

If I do not have room for a lever valve is a 15mm standard isolation valve what you shut off with a flat screwdriver sufficient for the ch feed off f n e ?

 

[terryplumb]

I wouldn't use one of that type of isolation valve ,better to have a full bore ,good quality,lever operated valve.

 

[diycooper]

I wouldn't use one of that type of isolation valve ,better to have a full bore ,good quality,lever operated valve.

Have you ever used a galo gun to unblock main cold feed ?

 

[terryplumb]

No , tried a shotgun once ,did the job but made a right mess of two walls
Seriously ,did you establish a blockage ?

 

[diycooper]

No , tried a shotgun once ,did the job but made a right mess of two walls
Seriously ,did you establish a blockage ?

Today put thermal camera on and it's obviously hot on feed. Got in loft to look at f n e. Ball valve was working. But the feed was bubbling.

I suspecting block on the t or faulty gate valve.

Thermostat is new and 3 port valve. Controls OK and turning pump off.

What you think. Block feed and expansion pipe ?

 

[terryplumb]

Possibly blocked,or partially at least.
If you have a strong magnet run it around the Tee in the Copper pipe,the pipes and compression Tee.
Any blockage ,or build up, of magnetite will attract the magnet.

 

[diycooper]

Possibly blocked,or partially at least.
If you have a strong magnet run it around the Tee in the Copper pipe,the pipes and compression Tee.
Any blockage ,or build up, of magnetite will attract the magnet.

I used magnetbat the t today although it was only a fridge magnet as I was waiting for a more powerfull magnet to gdt delivered. Which it has today. So will try the t again tomorrow.

If the magnet does not stick to the t tomorrow. Do you think I should check the gate valve first ?

I'm thinking a partial block myself.

 

[terryplumb]

Check gate valve for a blockage ? I think that's unlikely. Looks like you may need to do a bit of work to get to that gate valve.

 

[diycooper]

Check gate valve for a blockage ? I think that's unlikely. Looks like you may need to do a bit of work to get to that gate valve.

I can remove the front box to get at gate valve. Few screws amd the full piece of ply comes of.

I recently got a engineer to change 3 port valve. I think he may amd shut gate valve but unsure and maybe its stuck shut. Althoug the handle is spinning freely.

Do you mean unlikely the gate valve is blocked ?

 

[terryplumb]

I think it's unlikely that the gate valve is blocked with sludge / magnetite.
What do you mean by it's spinning freely ?
It should come to a stop when it reaches its closed, or fully open positions.
If it spins freely continually ,that's a problem.

 

[diycooper]

I think it's unlikely that the gate valve is blocked with sludge / magnetite.
What do you mean by it's spinning freely ?
It should come to a stop when it reaches its closed, or fully open positions.
If it spins freely continually ,that's a problem.

Sorry for confusing. It's spinning free left and right stopping each way.

Maybe partially blocked at T then water taking path of least resistance up the feed.

I think I'll bung the tank. Isolate water to f n e. Then clean f n e. After that open the t conpression and check if blocked.

Do you think this is what best to do first ?

 

[terryplumb]

Sounds like a good plan ,but I would also drain some water out so it's at a lower level than the Tee, otherwise you will have to contend with water leaking out when opening up the compression Tee.