Leaking Rifeng Flow Meter - Rust in system

MarkBK

I am helping my daughter and son in law. Recently they had the main circulator pump replaced. 30 days later they noticed a leak (3 feet away) and rust appearing in all the flow meters.

The contractor who did the work sent an estimate of over $ to fix the broken flow meter and flush just that one manifold.

I am thinking of doing the work myself instead. I am going to isolate the manifold and remove the cracked flow meter to photograph so that I can purchase the correct replacement. How should I deal with the rust that is now present in the system?

First pic shows the rust--the clear flow meter is an unused circuit. The manifold above the bucket is the leaking one.

MarkBK

PS This system had glycol in it. Some of that was lost when the pump was replaced I assume. We signed off on not using glycol going forward. The circuit to the garage was never connected up on the garage end, but was filled with fluid. It is shut off. It will never be used since there is a heat pump out there and no radiant loops or emitters. Puget Sound.

mattmia2

I'm guessing some of that tubing is not oxygen barrier and there was inhibitor in the old fluid that was lost when the circulator was replaced. either that or it was filled and not run to drive off the oxygen from the fresh water.

MarkBK

PPS The pump above the bucket is just a DHW recirculator. There is an air eliminator behind the DHW tank. I don't understand why there are two backflow preventers. Perhaps one is just for the outdoor bibs.

MarkBK

mattmia2 said:

I'm guessing some of that tubing is not oxygen barrier and there was inhibitor in the old fluid that was lost when the circulator was replaced. either that or it was filled and not run to drive off the oxygen from the fresh water.

It is reasonable to assume that some of the fluid was lost during the circulator replacement. The system fills from city water automatically and the air eliminator should have removed oxygen. The system was always running before and after the servicing.

Anyway what do I do now? After eliminating leaks should I obtain and add some inhibitor? What product? Is there any point in using glycol since freezing is not a risk?

hot_rod

I would not use glycol unless you absolutely need to

you need to flush out the old glycol. I would run a cleaner first, flush, refill and add a conditioner. Every few years test the fluid , possibly add more conditioner if needed

you will never have clear water in a system that has ferrous metals