Increasingly wild pressure fluctuations as hydronic system increases temperature

MikeAmann

While you are working on the plumbing is the time to add these convenience items, exactly as you suggested.

hot_rod

No reason why not to add service components

Ironman

The dirt mag doesn’t require disassembly like a strainer does: you simply blow it down at the drain port. There’s no strainer in it, just a coalescing media.

But if you wanna add valves, have at it.

hot_rod

We did have a larger size DirtCal that was returned with flow complaints. It had a brown cotton glove stuck against the media
I have also seen them jammed with Teflon tape shards
I consider both of those to be operator/ installer error

but had not the DirtCal stopped the junk, a pump or boiler opening may have😖

mattmia2

I guess there is the question why is it so filthy. Is there or was there glycol in this that hasn't had the inhibitors maintained?

np_mdbr

@mattmia2 I'm pretty sure the previous owners were adding tap water to the system via the reserve tank. I checked the composition with a refractometer and the freeze tolerance was pretty bad (around 28F). Since then, I have replaced about 20 gallons of fluid with brand new fluid and the tolerance is now around 2F.

mattmia2

Glycol as provided from the factory has corrosion inhibitors in it. There are test strips to test the effectiveness of those inhibitors. If they are depleted it will corrode things badly. You should test it and add an inhibitor package or change the glycol mix.

hot_rod

Mixing glycol with tap water compromises it, depletes part of the inhibitor package, as it tries to “fix” the tap water undesirables.
Maybe check and add a squirt of inhibitor boost. Test kits give you a good idea, a better analysis would be sending a sample to the manufacturer.