Find a water heater's failing check valve after other checks with Grok

Posted

May 13, 2026 by Jason Cox (@jasonbcox0)

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Last checked

Oct 18, 2026

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Method:

How we verify

Evidence: Described by posterThe person describes what happened in words, without screenshots or video.

Context: Another case on this site also traces a water heater fault with Grok; this one comes after the owner had already done the standard checks.

Outcome

After flushing the water heater, cleaning filters and checking error codes and sensors, the poster wasn't sure what to check next and asked Grok, which said that model has a check valve that often fails. Pulling it out solved the problem; the poster says it was an $8 part and saved $800 in repairs.

Agent

Grok

The source didn't share its exact prompt, so we wrote this from what it describes.

Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points.

Goal: Help me find what to check next on my water heater after the usual steps haven't fixed it.

What I can give you (ask for whatever's missing):
- Water heater brand and model
- What it's doing and any error codes
- Everything I've already done (flushing, filters, sensors)

Safety first: on a gas appliance, don't have me touch the gas valve, burner or venting; if I smell gas, tell me to leave and call the gas company. Unplug or switch off at the breaker before any panel comes off.

Rules:
- Don't repeat checks I've already done.
- Tell me about parts known to fail on my specific model, and how common the problem is.
- Give the part name and number to search for, and roughly what it costs.
- Mark any step that needs the gas or power off, or a licensed professional.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.

Output: The next two or three things to check, most likely first, with part details.

You'll know it worked when: the heater works normally again, or I know which part to ask a technician about.

Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points.

Goal: Help me find what to check next on my water heater after the usual steps haven't fixed it.

What I can give you (ask for whatever's missing):
- Water heater brand and model
- What it's doing and any error codes
- Everything I've already done (flushing, filters, sensors)

Safety first: on a gas appliance, don't have me touch the gas valve, burner or venting; if I smell gas, tell me to leave and call the gas company. Unplug or switch off at the breaker before any panel comes off.

Rules:
- Don't repeat checks I've already done.
- Tell me about parts known to fail on my specific model, and how common the problem is.
- Give the part name and number to search for, and roughly what it costs.
- Mark any step that needs the gas or power off, or a licensed professional.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.
- Say what you're basing 'commonly fails' on, so I can check it.

Output: The next two or three things to check, most likely first, with part details.

You'll know it worked when: the heater works normally again, or I know which part to ask a technician about.

Before you finish: re-read my goal and constraints, check your answer against each one, and list anything you assumed or couldn't confirm.

Source

https://x.com/jasonbcox0/status/2054629235202167084