Rebuild kit for wax based Heliotrope General SunSpool HG-SPOOL Drain Down Valve?

[brycenesbitt]

PXL_20210724_015700557.jpg

Where can a I find a rebuild kit for wax based Heliotrope General SunSpool HG-SPOOL Solar Thermal Drain Down Valve?
Anyone done this repair?


This was a 1970's era drain down valve.
When power is applied the wax gets warm the valve opens up allowing flow to the collectors.
When power is cut the wax cools, the valve closes and drains the pipe above to prevent freeze damage.

This one appears to be in fine condition, but the wax no longer operates, and in fact appears to be right there sort of stuck to the body.

As well:
anyone aware of a timer switch using an "atomic clock" or WiFi connection for keeping proper time?
The old timer switch in this system is.... something nobody will have patience to ever keep set any more in the age of TikTok.

[brycenesbitt]

I found this rebuild kit instruction manual (the kit is not available):
sunspool_instructions.pdf

The rebuild looks fairly challenging.
Can this be done without desoldering the entire valve?

[LucMan]

Time to modernize and simplify the control system. Parts for something this old are obsolete.
Convert to a drain back system.

[brycenesbitt]

Time to modernize and simplify the control system. Parts for something this old are obsolete.
Convert to a drain back system.

Ok. I see also https://www.sunnyhotwater.com/draindown.html

However, I doubt the owner of the system will pay for a rebuild of this system. So it's a new sunspool or maybe the system just never gets used again.
I've repaired sunspool valves before, just the rebuild kit I bought is no longer sold.



Replacing the tank with a heat exchanger model is not in the cards.
Can drain down be used with direct potable water?

[LucMan]

Drain down systems are a problem, too many components that can fail. There are drain back tanks that have a heat exchanger in them . AET dx drainback tank made by HTP. It's going to require some re-piping and a bigger pump. Maybe you can find a Johnson Controls, Honeywell, or Belimo electrical powered valve to replace the defective one.
Costly repair either way.

[brycenesbitt]

Drain down systems are a problem, too many components that can fail. There are drain back tanks that have a heat exchanger in them . AET dx drainback tank made by HTP. It's going to require some re-piping and a bigger pump. Maybe you can find a Johnson Controls, Honeywell, or Belimo electrical powered valve to replace the defective one.
Costly repair either way.

Looks like JED Engineering is still doing sunspool repair parts:
https://jedengineering.com/products/...nd_repair_kits

The three failing components are likely the pump, the drain down valve and the air valve up top. The rest is common with a drain back system.

Does anyone make a atomic clock time clock, to replace the mechanical timer clock? One with atomic time setting and astronomical estimation of day/night cycles?

[azdave]

Does anyone make a atomic clock time clock, to replace the mechanical timer clock? One with atomic time setting and astronomical estimation of day/night cycles?

Not atomic referenced but accurate enough for me. I use astronomic in-wall digital porch light timers when I need a timer that follows the sunrise and sunsets for my latitude throughout the year. On the model I use, I can also offset the trigger points to be earlier or later than the calculated sunrise/sunset times. They also have a temporary manual mode and a full manual mode. These are normally used as porch light timers of course.

Here is one model at Lowes.

https://www.lowes.com/pd/TORK-Timers-Digital-Lighting-Timer/1000341251

[brycenesbitt]

Not atomic referenced but accurate enough for me. I use astronomic in-wall digital porch light timers when I need a timer that follows the sunrise and sunsets for my latitude throughout the year.
https://www.lowes.com/pd/TORK-Timers...mer/1000341251

Cool. You still have to set the time thought, right? Are you aware of any that are Internet connected or use the WWV signal for time?

Drain down systems are a problem, too many components that can fail. There are drain back tanks that have a heat exchanger in them . AET dx drainback tank made by HTP. It's going to require some re-piping and a bigger pump.

I'm looking at replacing the sunspool HG-SPOOL with a Invensys/Eaton/Dole
Lead-Free Freeze Protection Valve Model FP35-SE-2
That way it does not need to drain down most nights, just the cold ones.
p_fp45_d.gif


The system is two 150 gallon tanks, 40 feet of head to four panels through 3/4" pipe. Currently a Grundfos UP 25-64 pump with plastic impeller, perhaps a bit low on the static head.

I was able to rebuild the Grundfos pump. It has sat seized up for at least a decade, probably more. On removing it I found enough sort of biofilm had formed on the inside to keep it from spinning. A wipe (and quick trip through the dishwasher) and it's running again.

[LucMan]

Is this system for a space heating application? Just wondering because you state that you have two - 150 gallon tanks and 4 panels.

[brycenesbitt]

Is this system for a space heating application? Just wondering because you state that you have two - 150 gallon tanks and 4 panels.

No.
It's an 11 unit apartment building for domestic hot water. The two 150 gallon takes are arranged as a pre-heater to a conventional commercial gas water heater.
I don't own the system, did not design it. I saw it languishing and am volunteering to get it back up and running just because....

[azdave]

Cool. You still have to set the time thought, right? Are you aware of any that are Internet connected or use the WWV signal for time?

You still have to set the time at least once. I have three of these timers in use and have not needed to adjust any of them after 7 years in use. I'm sure they have drifted a little but not enough for me to notice. They keep far better time than my pool and irrigation timers. I don't know of any of that type that are self-adjusting by referencing a more accurate time signal.

[brycenesbitt]

Here's a source for replacement heat motors for the Sunspool valves:

MARTIN W BRANDALICK
solarmarty@sbcglobal.net
Sonoma County, California

Marty says the new heat motors last about 10 years (about the same as the originals). They're of course non-electronic, so when they fail all you know is the valve won't open fully.