leaking manifold valves

[joeirish]

I've had my UFH system in and running for six years now. Today I once again had to replace one of the valves (the ones under the actuator). I have eight valves in total on the manifold and over the years I have so far had to replace six of these. Basically what happens is that the valve starts leaking when the actuator is in the down position. Rusty water comes out around the pin at the top of the valve. My plumber has no idea why this is happening. There is plenty of inhibitor in the system. Just wondering if anybody had any ideas?

[ProDave]

If it is rusty water, there might not be enough inhibitor.

 

What pressure is the system charged to?  Is your expansion vessel okay (plumber should have checked that)

 

What make of manifold?  Picture?

[joeirish]

Thanks for the reply. The manifold is by Ivar (https://www.ivar-group.com/en/UK/products/Manifolds-8524).

 

Attached is a photo.

 

The pressure only drops when the valves are leaking. Otherwise holds steady at about 1.5 bar.

 

The plumber checked the fluid today when he was changing the valve and said there was "industrial amounts of inhibitor" judging by what came out and the smell!

Edited August 10, 2021 by joeirish

[RHayes]

Hello Joeirish

 

Thanks for the photo.   I have come across these manifold valves leaking before but not to that frequency or repetativeness that you seem to be having.  Have you concidered upgrating or renewing the manifold?  Are there any valves that you have had to replace more than once out of the 8?  If not then it may be a batch problem from the original manifold batch.  Just a thought.

 

If you'd like to change the manifold would be happy to recomend. 

[dpmiller]

there might be inhibitor, but those flow gauges sure look stinky. I wonder if the residue is building up on the valve pin and then scoring the sealing O-rings...

 

 

Is your water mains or well, and was it pre-treated with anything prior to filling the heating system? What does the inside of your kettle look like?

[joeirish]

2 hours ago, dpmiller said:

there might be inhibitor, but those flow gauges sure look stinky. I wonder if the residue is building up on the valve pin and then scoring the sealing O-rings...

 

 

Is your water mains or well, and was it pre-treated with anything prior to filling the heating system? What does the inside of your kettle look like?

We have a well which is fairly neutral, kettle doesn't fur up that much. I suspect that something is building up and wearing down the sealing rings.What type of residue to you mean. My plumber's most recent fix has been to deal with possible eletrolysis. We had copper pipes going to and from the boiler and stainless steel coil in the thermal store. So he has put some plastic piping in the circuit to see if that will break up the electrolysis, if that is what's causing this residue.

[joeirish]

3 hours ago, RHayes said:

Hello Joeirish

 

Thanks for the photo.   I have come across these manifold valves leaking before but not to that frequency or repetativeness that you seem to be having.  Have you concidered upgrating or renewing the manifold?  Are there any valves that you have had to replace more than once out of the 8?  If not then it may be a batch problem from the original manifold batch.  Just a thought.

 

If you'd like to change the manifold would be happy to recomend. 

I did wonder about upgrading/renewing the manifold. I think I had to replace one valve twice but the others only once so far. Everything was fine for the first couple of years  (not sure exactly when this frist happened!) then the first valve started leaking. I live in Clare but would be interested in hearing your recommendations.

[joeirish]

Just taken a photo of the pin valve that my plumber replaced yesterday in case anybody has any thoughts.

[dpmiller]

Have you ever had the well water tested for iron?

[joeirish]

6 minutes ago, dpmiller said:

Have you ever had the well water tested for iron?

Yes that's been done. In fact the testing showed it to be really good water, not too hard and not too soft with no iron or other metals. Tastes wonderful too!

 

My plumber wondered if there was some sort of electrolysis going on. The unf fluid circulates through the boiler which is steel and then trhough copper pipes and then throught stainless steel coil in the thermal store. The ufh pipes I believe are lined with plastic so should not effect things.

Edited August 11, 2021 by joeirish

[joeirish]

And this is the ufh underfloor piping that was used

 

https://shop.ivt-group.com/de-de/prineto-flächenheizrohr-stabil-16x2-0-pe-s-al-pe-878311442

 

The description when translated says "Multi-layer composite pipe PE-S / Al / PE-RT, inliner made of self-crosslinking polyethylene, oxygen-tight by means of aluminum sheathing, top layer made of polyethylene with increased temperature resistance, for use in surface heating according to application class 4, compression with brass-colored sliding sleeve 16 "

 

 

[PeterW]

20 hours ago, joeirish said:

We had copper pipes going to and from the boiler and stainless steel coil in the thermal store. So he has put some plastic piping in the circuit to see if that will break up the electrolysis, if that is what's causing this residue.

plumber doesn’t understand electrolysis. It happens when 2 dissimilar metals are connected by a electrolyte - they don’t need to be touching. 
 

On 10/08/2021 at 19:00, joeirish said:

The plumber checked the fluid today when he was changing the valve and said there was "industrial amounts of inhibitor" judging by what came out and the smell!

Inhibitor doesn’t smell, but sulphates of iron do. I think this is more about the water going into the system to start with and not enough inhibitor rather than too much. 
 

On 10/08/2021 at 19:00, joeirish said:

Attached is a photo.

Who marked that up..? Item marked as a “pressure valve” is an automatic air bleed valve. 

[Temp]

You might be able to get a test kit to measure the inhibitor concentration but I think these are specific to the make of inhibitor?..

 

https://www.bes.co.uk/sentinel-x100-central-heating-test-kit-7583/

 

https://www.plumb2u.com/fernox-62514-express-inhibitor-test-c2x32812924

 

Next time it gets drained measure the volume of water and work out how much corrosion inhibitor is needed. Depending on how your TS works you heed quite a few bottles of the stuff.

[joeirish]

3 hours ago, PeterW said:

Who marked that up..? Item marked as a “pressure valve” is an automatic air bleed valve. 
 

Thanks for the reply. I smelled the inhibitor he had with him and it dedeinfeletly had a smell as did the fluid that came out of the system when he was changing the pin valve.

 

I wondered about the iron in the water but we had our well water tested a while ago and the amount of iron in it is quite low (Iron,Total  15 ug/l.   PV Value 200 µg/l). However there is high alkalinity so maybe this is an issue?

 

I'm afraid it was myslef who marked up the photo. That was a mistake I now see that the pressure valve should be labelled differently/correctly.