[RE-wrenches] flushing DHW collectors

[August Goers]

Kirk,



Any idea what kind of glycol was in the system? I’ve seen systems stagnate
for several years where the propylene glycol was still fine if it was good
quality. I’ve seen people use the automotive grade propylene glycol such as
Sierra brand antifreeze with poor results.



I think Glenn’s suggestion of flushing with a TSP solution is a good way to
go.



Good luck, sounds like a messy situation!



Best,



August



*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *Kirk Herander
*Sent:* Friday, April 17, 2015 10:21 AM
*To:* RE-wrenches
*Subject:* [RE-wrenches] flushing DHW collectors



Hello,



I have an older 10 collector system in which the glycol has stagnated due
to a defective collector sensor, apparently for some time. I was able to
drain the collectors, the cooked glycol is black with a good bit of
sediment. I tried to flush the system with water but my ½ hp utility pump
could not pump the water entirely through the collectors. Suction slowed
down and stopped after just a few gallons, as if the pump couldn’t overcome
the effective head of the system. I had no problem using this pump to
charge the loop when it was commissioned. I suspect the collectors may be
gummed up with cooked glycol. I guess compressed air is next to try. Are
there any safe chemicals to use to purge / un-gum the collectors? Thanks.



*Kirk Herander*

*VT Solar, LLC *

*Proven PV provider since 1991*

*www.vermontsolarnow.com <www.vermontsolarnow.com>*

dba Vermont Solar Engineering

NABCEPTM Inaugural Certificant

VT RE Incentive Program Partner

802.863.1202
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