Radiant in-floor - Sludge, full reservior, glycol

Taurk

Hello,

I have a radiant in-floor heating system that we installed when the house was built new 6 years ago. I noticed water coming out of the vent pipe coming off the boiler and when I started looking to cause, I found a lot of sludge building up in the vent trap. Upon further investigation, the reservoir that holds the glycol is FULL; it wasn't 6 months ago during the summer months.

The system is still keeping my basement and garage at temperature, but I'm quite concerned with these symptoms. Any ideas on what would cause the reservoir to fill up? Sludge? Related?

Thank you in advance for thoughts and ideas.
Scott

Jamie Hall

Reservoir? Vent pipe? Vent trap? eh?

SuperTech

Reservoir for glycol? Do you happen to know the model of the boiler? Pictures would be helpful. 

Zman

Some pictures would help. I have seen setups where they pipe the relief valve back into the glycol pig. That would explain your symptoms.

hot_rod

A few things that cause glycol to go bad or sludge, overheating on a regular basis, and exposure to air, oxygen really.
Non barrier tubing of any type can ruin glycol quickly.

Glycol really needs to be kept in a sealed air tight container to prevent the inhibitors from breaking down.

One last think is putting glycol in a dirty system causes it to deteriorate quickly also.

If all three of these condition exist, glycol can turn on you in a few months time. A yearly ph test will let you know when it is going south.
Some pics would help

KNPV_PSD

hot_rod said:

A few things that cause glycol to go bad or sludge, overheating on a regular basis, and exposure to air, oxygen really.
Non barrier tubing of any type can ruin glycol quickly.

Glycol really needs to be kept in a sealed air tight container to prevent the inhibitors from breaking down.

One last think is putting glycol in a dirty system causes it to deteriorate quickly also.

If all three of these condition exist, glycol can turn on you in a few months time. A yearly ph test will let you know when it is going south.
Some pics would help

Sorry to bring this back from the archives, but it covers exactly my question...when using an automatic glycol reservoir should the reservoir glycol be changed out routinely? Or just keep straight H2O in it since it will be a minor amount?

hot_rod

KNPV_PSD said:

hot_rod said:

A few things that cause glycol to go bad or sludge, overheating on a regular basis, and exposure to air, oxygen really.
Non barrier tubing of any type can ruin glycol quickly.

Glycol really needs to be kept in a sealed air tight container to prevent the inhibitors from breaking down.

One last think is putting glycol in a dirty system causes it to deteriorate quickly also.

If all three of these condition exist, glycol can turn on you in a few months time. A yearly ph test will let you know when it is going south.
Some pics would help

Sorry to bring this back from the archives, but it covers exactly my question...when using an automatic glycol reservoir should the reservoir glycol be changed out routinely? Or just keep straight H2O in it since it will be a minor amount?

Glycol should always be stored in a closed, sealed container according to Dow and other manufacturers.

Those fill tanks to my knowledge are not sealed air tight.

So oxygen gets to the glycol and consumes some of the O2 scavenger inhibitor.

Of course if the system never takes on additional fluid, not much worry.

Certainly no harm in testing, or replacing the fluid every few years. A couple gallons??

Test the system fluid while you are at it, the Ph will tell if the fluid is going bad.

You can buy boost kits for hydronic glycol if the Ph hasn't slipped too much.

Any water that could get added will lower your freeze protection. May as well test that also. I like the refractometers better then floating ball type or color strips to get an exact protection number.

KNPV_PSD

Correct, the tank is vented to allow the pump to draw from it. I figure that if the system is running correctly it won’t be adding any significant amount from the reservoir. I have a refractometer so I’ll just check it every season. Thanks for the help.