What's this fitting next to circ pump?

CBRob

Looks like a screw or rivit?
Seems to be the source of the leak...

Alan (California Radiant) Forbes

That's an old style shutoff valve that's part of the pump flange, made so that you can isolate the pump in case you need to work on it. It's common for them to leak, especially when you turned the valve after a few years in service.

Taco and Grundfos were the first ones I saw that came out with them and they were a great idea, but more often than not, the valves would freeze and become useless.

hot_rod

And if you turn them, they tend to leak more Needs to be replaced, there are better options now, Webstone is one brand, most all the pump manufacturers offer iso flanges.

CBRob

They are all a little leaky in this 20 year old boiler room.

Solid_Fuel_Man

Looks like you have glycol in that system.

CBRob

> @Solid_Fuel_Man said:
> Looks like you have glycol in that system.

I'm in the coldest county in Colorado..
We put glycol every where it seems.
Even inside the house when regular h2o would be fine.
This system is 20 years old now...
Bracing the owner for the inevitable replacement that is looming.

unclejohn

I prefer to use a seperate ball valve at the pump.

Solid_Fuel_Man

Glycol needs maintenance. I view it as a bandaid to poor piping or many drafts. I live climate zone 7. And I dont have or put glycol in good systems.

mikeg2015

It only takes one power outag, or foreclosure and improperly winteriezed home to freeze and destroy a radiant system. We put glycol in everything even here in zone 5.

Exceptions are older legacy CI radiator systems. Old oversized steel pipe is harder to freeze and burst than copper. And also wood boiler systems.

Keep in mind that Zone 7 will typically have different home construction and more insulation due to it’s climate, so zone 5 where it’s a shorter winter but can still reach -10F or stay below 0F for 24 hours 1-2 times a winter and more power outages due to ice and wind storms, I suspect there’s actually a higher risk of freezing. Just something to consider.

Also garage installs for boilers are common on frame building style homes. And floor heat in garages are common. Many homes are on propane. So if tank runs out and company cant get there, you can’t drain the in floor loops without compressed air.

mattmia2

Or a shop vac. A shop vac is good at sucking higher volumes unless you have a rather large compressor.

pecmsg

Solid_Fuel_Man said:

Glycol needs maintenance. I view it as a bandaid to poor piping or many drafts. I live climate zone 7. And I dont have or put glycol in good systems.

Agreed like everything else maintenance is required and often overlooked or poorly performed.

No glycol in my personal system but I pitched all piping so draining is fairly easy if ever needed.

If all piping is in conditioned space its up to the customer but is offered. On HW coils in attics in this market Glycol with 20 - 25°F freeze protection is SOP.

hot_rod

Most important glycol needs to be put in a clean system, with pre-mix or diluted with DI water at the site. If not the glycol is pretty compromised from day one. No O2 ingress either. Store glycol in sealed containers or the O2 will ruin it.

A yearly ph is a good indicator of when it needs a boost or flush, the O2 scavengers get depleted.

Solar glycol should be checked at least yearly, it leads a tough life at stagnation temperatures in excess of 400F.

CBRob

> @hot_rod said:
> Most important glycol needs to be put in a clean system, with pre-mix or diluted with DI water at the site. If not the glycol is pretty compromised from day one. No O2 ingress either. Store glycol in sealed containers or the O2 will ruin it.
>
> A yearly ph is a good indicator of when it needs a boost or flush, the O2 scavengers get depleted.
>
> Solar glycol should be checked at least yearly, it leads a tough life at stagnation temperatures in excess of 400F.

What pH should I see for glycol that is still adequate?
on this particular house I'm guessing the glycol is the original from 20 years ago.
When glycol goes bad what exactly happens?
Does it lose some of its antifreeze capability? Anything else?

hot_rod

9.5- 10.5 is the Ph out of the bucket. If it drops into the 8's usually it can be salvaged with an inhibitor boost, into the 7's may be best to flush, run a cleaner and start over.

When Ph drops it becomes aggressive to the metals, pinholes, also sludge formation.

If it is coffee colored and a harsh smell that is a good indicator that is needs some attention.

Some of the best glycol info here. Use only inhibited PG fluids if it has any potential to contact DHW, Dowfrost™ for example.

https://www.dow.com/content/dam/dcc/documents/en-us/app-tech-guide/180/180-01286-01-engineering-and-operating-guide-for-dowfrost-and-dowfrost-hd.pdf?iframe=true

Zman

mikeg2015 said:

It only takes one power outag, or foreclosure and improperly winteriezed home to freeze and destroy a radiant system. We put glycol in everything even here in zone 5.

Exceptions are older legacy CI radiator systems. Old oversized steel pipe is harder to freeze and burst than copper. And also wood boiler systems.

Keep in mind that Zone 7 will typically have different home construction and more insulation due to it’s climate, so zone 5 where it’s a shorter winter but can still reach -10F or stay below 0F for 24 hours 1-2 times a winter and more power outages due to ice and wind storms, I suspect there’s actually a higher risk of freezing. Just something to consider.

Also garage installs for boilers are common on frame building style homes. And floor heat in garages are common. Many homes are on propane. So if tank runs out and company cant get there, you can’t drain the in floor loops without compressed air.

I really don't agree with this reasoning. It literally takes days to freeze a house, even in cold weather in zone 7. Even if you glycol the heating system, what prevents the domestic water from freezing and flooding the home? It is so much easier to mitigate the issue with monitored low temp and boiler fault alarm.

In my mind, glycol is for hydronic coils exposed to outdoor air, snow melt systems and second homes where owner can't or won't monitor.

CBRob

Thank you hot rod.

As far as potential contact with domestic water, it's only a backflow preventer away.

If a house goes without glycol, is there a water treatment that is beneficial to the hydronic system?

Solid_Fuel_Man

It is always beneficial to use a cleaner and then a hydronic water treatment. I've used Sentinel x100 for example. There are several chemical companies who manufacture hydronic additives.

Solid_Fuel_Man

As a note on my (and others) sentiment about glycol in hydronic systems. Last year I replaced a copper pipe which had repeatedly frozen when the wind was blowing out of the east and it was below zero for a customer. This pipe was in a closet which fed baseboard in a dormer, 1970s construction. The pipe was replaced with some Armaflex sleeved PEX and I spray foamed some cracks while I was on my belly with arms extended straight out. Customer had another contractor add glycol to stop the freezing but it was never maintained and caused a zone valve to leak (why I was there).

I made the repairs, flushed the entire system, tested etc and he has not had a free up since and it's been well below zero and windy since the fall of 2018.

hot_rod

> @CBRob said:
> Thank you hot rod.
>
> As far as potential contact with domestic water, it's only a backflow preventer away.
>
> If a house goes without glycol, is there a water treatment that is beneficial to the hydronic system?
>
I would not connect any glycol system to a fill valve, too much potential to dilute the mix.

Rhomar is a local company, I’ve seen the care and testing they have done to assure their products are top quality and multi metal friendly, a tall order. I’ve also seen the results of bargin glycols and treatments.