This is odd

[joemach]

I have 2 Water Furnace customers who have called a day apart with a Water Flow light coming on.

Never seen this before, where 2 of the same issues happen 35 miles apart at 2 separate sites. Both residential. Both Water Furnace.

We have has quite a warm winter and spring.

Would anyone have any idea what is going on?

I have not been to either site yet.

[joemach]

I have 2 Water Furnace customers who have called a day apart with a Water Flow light coming on.

Never seen this before, where 2 of the same issues happen 35 miles apart at 2 separate sites. Both residential. Both Water Furnace.

We have has quite a warm winter and spring.

Would anyone have any idea what is going on?

I have not been to either site yet.

Anyone?

[RLJN]

Loop or pump and dump?

[joemach]

Loop or pump and dump?

Pretty sure loop. Have not been there in a few years.

[RLJN]

Would the ground frost have reached it's deepest point now and just starting to come back up?

Snow cover this year or not?

[joemach]

Would the ground frost have reached it's deepest point now and just starting to come back up?

Snow cover this year or not?

Very little snow.

[VTP99]

Those aren't auto fill are they ?

[joemach]

Those aren't auto fill are they ?

NO

[RLJN]

Glycol getting slushy??

[VTP99]

First though , leak .

[joemach]

First though , leak .

On both systems, at the same time?

What else?

[hvacvegas]

On both systems, at the same time?

What else?

expansion and contraction in the loop.
The pipe in the ground during the season will expand as it gets warm in summer, adding in the heat added to the water pushes the water pressure up.

Winter, pipe shrinks, water pressure decreases due to less heat.

This happens season by season, as long as you started straight up at about 40-50 psi, no problem.

One summer, the pipe will expand....and not shrink back. Which is good. You'll be making more contact with the ground with more surface area.

Winter comes, doesnt shrink back, water gets cold, shrinks, you loose pressure to the point your not pumping anymore.
Especially if the geo is in the basement, and the water lines go up the wall before exiting the building into the trench.

Bump it up. Call it a day. Dont worry about adding anti-freeze, you haven't really added any water. Maybe a quart.
If it drops again, then yeah, you are leaking somewhere.

DONT ASSUME ITS THE LOOP LEAKING!
When your done bumping it. Stick around and watch it run. See if your getting leaking at the pumps. Happens all the time.

[joemach]

expansion and contraction in the loop.
The pipe in the ground during the season will expand as it gets warm in summer, adding in the heat added to the water pushes the water pressure up.

Winter, pipe shrinks, water pressure decreases due to less heat.

This happens season by season, as long as you started straight up at about 40-50 psi, no problem.

One summer, the pipe will expand....and not shrink back. Which is good. You'll be making more contact with the ground with more surface area.

Winter comes, doesnt shrink back, water gets cold, shrinks, you loose pressure to the point your not pumping anymore.
Especially if the geo is in the basement, and the water lines go up the wall before exiting the building into the trench.

Bump it up. Call it a day. Dont worry about adding anti-freeze, you haven't really added any water. Maybe a quart.
If it drops again, then yeah, you are leaking somewhere.

DONT ASSUME ITS THE LOOP LEAKING!
When your done bumping it. Stick around and watch it run. See if your getting leaking at the pumps. Happens all the time.

Mr. Vegas,

Thanks! Great info.

Bumping it up was about where I was going to start. So that confirms my thoughts.

Now that I recall I had a similar one a few years ago that I only added a quart or so to handle this issue. I think your response jogged my memory on that one.

Your help is appreciated.

[Bill Lee]

If both systems were in heating mode and water flow light came on, this means that temperature of water/refrigerant hx has reached less than 15 deg for closed loop or 30 deg for open loop. Could be low water flow from loop side or on an older WF unit low on refrigerant from leaky air coil. If units were in cooling mode, low water flow would normally be indicated by a high pressure fault light (loss of outside fan motor or dirty condenser coil on and air-air system).

[joemach]

So I added less than a pint of water to the one system and all was good.

On the second one, I added a few oz. of R-22 and all was good. I checked for leak, but could not find one. Pressure was a little low.

Watched it run with no issues for over an hour. Next day, customer cales and low pressure fault again.

This is 2 stage with dual pumps for the well. It seems at one point during diagnosis that only one of the pumps was running, But at other times they were both running and at others times none were running.

Any thoughts, ideas, suggestions?

[DeltaT]

Sometime, and just sometimes if these systems use pressure switches to indicate water flow the calcium or other material can plug up the line to the pressure switch, typically 1/4", and cause a fault even though nothing is wrong with the unit. Remove the line to the pressure switch to see if there is any build up. Most any swimming pool place has those switches if you can't find them anywhere else. I have a few machines that do this about every two years. I just put new switches on and clean out the taps.

[Bill Lee]

WaterFurnace geo hp's don't use water pressure switches, they use thermistors to sense line temperatures. With this being a two-stage hp, is it the old Bristol TS compressor, or a Copeland two-stage scroll? The TS system did use staged flow center pumps for systems 4 tons and up. The Copeland scrolls bring both pumps on for stage one. If the units are the Primer E models (with the TS compressors) and have had a scroll replacement kit installed, be sure to check the pumps wiring at the control board and at both pumps. I was assisting an area Tech following up such a compressor replacement job. The original installer's electrictian had run a three wire BX cable from the unit to the pumps, using black and white wires for stage 1 and stage 2 pumps and the green wire for common on one side of the 240 wiring (and not to NEC!). The tech wired the control board end as one would--green to equipment ground and white and black for 240. At the pumps end, this put the two pumps in series and caused one pump to overheat. It got so hot that it melted the GL fitting on top of the flow center, as well as the o-rings on the three-way-valve. We found this after replacing the defective pump and trying to pressure up the loops. Ended up having to replace the flow center itself.