Always turn off the hot and cold taps on the outside (dog wash) faucet, not just the spray head valve. This is a known cause for allowing hot and cold water lines to mix and possibly reduce the water pressure flowing from only hot faucets. The other thing to check is make sure your winter bypass valves are fully in their Summer positions.
We need more information on the other poster's Girard problem. Did it just start having a problem; does it try to fire but fails to light etc.
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