Expansion tank with no isolation valve
#1
12-10-06, 05:51 AM
Expansion tank with no isolation valve
Is there any way to drain an expansion tank that has a drain but no isolation valve without having to drain the whole system? Seems to me like Grady posted something about this once (at least), but I'll be darned if I can find it in a search. Thanks. Bill
#2
12-10-06, 02:34 PM
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First turn off the valve that feeds water to the system. Then if there are any automatic air vents on the system, close the caps on them. Then, open the drain valve on the expansion tank and drain into buckets. If you use a hose, it will probably take forever. If you have a 3 foot piece of hose, you can use that and alternately blow air into the tank and then let the water flow into the bucket. If you don't find a way to get air into the tank, it won't drain. When it is empty and you are sure it is, close the drain valve and re-open the feed valve to the system and any air vents that you may have closed. You should be back in business. Every time I see an expansion tank installed that way, I just wonder what installer could be ignorant enough to do it. Certainly not someone with a shred of common sense.
Ken
Ken
#3
12-10-06, 04:01 PM
Thanks, Ken; I'll give it a try this evening. Unfortunately, the isolation valve was the single item that slipped through the cracks last January when I had a new boiler installed. This was an "after hours" job by a friend of mine and his helper, and it took all 3 of us, a rather long length of cheater pipe and a 5lb sledge to disassemble the old 2 zone outlet manifold so we could tie in the new boiler. The best of intentions, but we sort of got caught up in the heat (no pun intended) of the moment and never thought to get back after it. Those were the toughest d___ fittings I have ever run into! -- Bill
#4
12-10-06, 05:12 PM
Worked like a charm, Ken! Some huffin' and puffin' and 25g of water later, I believe we're cookin' on the front burner again. You probably saved me at least $50.00. Many thanks. -- Bill
#5
12-12-06, 04:58 PM
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valve
Honeywell makes a small inline automatic valve that mounts between the tank and airvent. Can save a lot of problems in the future.
