Thx
Heat Riser Valve open or closed?
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
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Cruise-In VIII Veteran
No vacuum to heat riser. Are you asking about hot water shut off?
Safety Car
Joined: Oct 2007
Posts: 4,380
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From: Seattle Area Washington
Once engine coolent is at or around 180*F the TVS switch then closes and remaining vacuum in the circuit is exhausted through the exhaust port of the TVS switch, heat riser is open.
The normal or home position of the heat riser valve with NO vacuum is open.
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