Are check valves really necessary?


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Old 04-11-13, 07:22 PM
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Are check valves really necessary?

My hot water heating system has three zones. Two have Taco 218 check valves and one has a Taco 219 check valve. All are corroded and leaking. The system initially had a tankless coil for hot water, but this is no longer functional, as we now heat hot water with a standalone water heater. My old house, which also had a similar heating system, did not have any check valves, although it only had a single zone. Similarly, my kids' house, which is similarly heated, has two zones and an indirect water heater, and does not have any check valves. My question is, if I don't care about leakage from one zone to another, do I have to have check valves? Thanks in advance for your thoughts.
 
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Old 04-11-13, 07:56 PM
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My question is, if I don't care about leakage from one zone to another, do I have to have check valves?
If you dont care then no you dont have to have them. Your system may work as one big zone then. Turn on one t stat and get heat at the other zone also. may waste fuel also.

We really need to see the system. You cant go by your old house. That may have had check valves built into the circs, and/or zone valves instead of circs....

Others will chime in but take a few pics.....
 
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Old 04-11-13, 08:09 PM
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I can't get a picture because I am not at the house and won't be there for another three or so weeks. However, the layout is as follows on each zone: Boiler - circulator - shutoff valve (with no drain) - drain valve with hose bib - check value (Taco 218 or 219) - shutoff valve (with no drain valve). Obviously, this is not ideal, as I would prefer to have a shutoff before the circulator, but that's the way it is.
 
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Old 04-12-13, 05:10 AM
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You say that the system is 'zoned'... yet there is no mention of electric zone valves, and it is unclear if there is a circulator for each zone.

The flow check valves are not only for 'bleed' from one zone to the other, but also to prevent 'thermo-siphon', 'gravity flow', 'ghost flow', or whatever you want to call it. These terms refer to hotter water 'floating' up into the system from the boiler and continuing to provide heat to the home after the thermostat is satisfied.

Describe the system in a bit more detail and we can give better advice.
 
 

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