Troubleshooting and
Decision Making
for routine maintenance and repairs
Assumptions
•
•
•
•
•
•
•
We are busy!
Know what to do, know the trade
Short staffed
Backlog of work
New work orders every morning
Quickest fix, come back later...
Go on to the next job
Problems
•
•
•
•
•
•
Rapidly changing technology
Inadequate training
Afraid to ask for help
Limited access to as-built drawings & manuals
Limited access to the internet
Limited testing equipment
Scenario 1
“Not a roof leak after all…”
Scenario #1
•
•
•
Ceiling tile stained from water leak.
Reported as roof leak due to previous history.
Ceiling tile replaced and roof patched multiple times?
Findings
• Not all water damage was from roof leaks.
• Water leaking and running along metal bar joist.
• Cold solder joint found.
Cold Solder Joint
Results
• All similar piping and equipment installations were
inspected.
• Future ceiling tile issues may not all be roof leaks.
• Findings of cold solder joints were communicated to
all shops.
Potential Pitfalls
•
Conformation Bias
‒ “the tendency to search for, interpret, or
recall information in a way that
confirms a belief or hypothesis”
Scenario 2
“Cold Showers.”
Scenario #2
•
•
•
•
•
Two 50 year old, 1500gal hot water tanks were a
part of a scheduled shutdown, both came back
slowly.
Several months later one of the water heater
bundles had to be replaced.
HW not reaching showers in the gym after single
HW tank started up.
All isolation valves were checked.
Everything was on, and still no hot water.
Action
•
•
•
Prints reviewed to verify flow of all unmarked pipes.
Boiler temperatures were verified by removing
insulation to at strategic location. Used infrared
camera to check temps.
Tanks and piping in mechanical room was all up to
temperature, still no hot water to showers.
Tools & Testing Equipment
• Infrared Camera
Finding
• Found gate valve isolated to the unused tank even
though stem showed the valve was open.
• Valve stem was separated from internal gate,
causing no hot water to pass through to the showers.
Issues Complicating Solutions
• Very old system.
• Parts of the system abandoned or bypassed years
before.
• New mechanics lack knowledge of the building loop.
• Previous contractors work in the building since we
performed our maintenance.
• Drawings for the building not maintained.
Results
• Night time mechanical shutdown of all water to gym
was scheduled for gym convenience.
• Valve bonnet was removed and stem had pulled
through gate slot.
• Gate was removed bonnet reinstalled and tagged
inoperable.
• Push to expedite replacement of the aged HW
system.
• Additional gauges installed to verify temperatures.
Potential Pitfalls
•
Groupthink
‒ “the tendency to think or make
decisions as a group in a way that
discourages creativity”
•
Incomplete Information
Problem Solving?
• Is there anything we can point to as a general
problem solving method in this case?
Seven Steps to Problem Solving
• 1. Problem: Any service call or system malfunction can use this process for all
your trouble shooting needs.
• 2. Problem Statement: Define the problem. Be specific. Keep the scope small
and to the point. (Room always to hot- resetting a boiler every other day)
• 3. Ask Why 5 Times & select countermeasures: Start with the problem
statement.
–
–
–
–
–
a. Ask why it happened.
b. Ask why until you have found the root cause.
c. Asking why 5 times often gets to the root cause.
d. Discuss and select the new process that will ensure you don’t have this problem again.
e. Addressing the true root causes prevents, or at least minimizes, the problem
Seven Steps to Problem Solving
NCAPPA HVAC presentation
Seven Steps to Problem Solving
• Problem Statement:
– Multiple work orders from a new space that was just
renovated having “hot and cold” issues.
Seven Steps to Problem Solving
HVAC
presentation
Multiple work orders from a new space NCAPPA
that was
just
renovated having hot and cold issues.
Seven Steps to Problem Solving
• 1st Why:
– Why is the room too hot?
– Is the T-stat calling for heat?
Seven Steps to Problem Solving
is the room too hot? Is the T-stat calling for heat? (No.)
NCAPPA
Multiple work orders from a new space
thatHVAC
waspresentation
just renovated having hot and cold
issues.
Seven Steps to Problem Solving
• 2nd Why:
– Why is the heat on if the T-stat is not calling for heat?
– Is the valve stuck?
Seven Steps to Problem Solving
is the heat on if the T-stat is not calling for heat? Is the valve stuck? (No)
is the room too hot? Is the T-stat calling for heat? (No.)
NCAPPA
Multiple work orders from a new space
thatHVAC
waspresentation
just renovated having hot and cold
issues.
Seven Steps to Problem Solving
• 3rd Why:
– Why else would the system continue to run? Signal
from BAS?
– Why would the unit be dehumidifying?
Seven Steps to Problem Solving
is BAS running dehumidification cycle? (Room has a humidity set point that was not
updated when room was renovated.)
is the heat on if the T-stat is not calling for heat? Is the valve stuck? (No)
is the room too hot? Is the T-stat calling for heat? (No.)
NCAPPA
Multiple work orders from a new space
thatHVAC
waspresentation
just renovated having hot and cold
issues.
Seven Steps to Problem Solving
• 4th Why:
– Why would the room need a humidity set point?
Seven Steps to Problem Solving
would the room need a humidity set point? (The room has a high humidity
problem or the room was designed for book storage).
is BAS running dehumidification cycle? (Room has a humidity set point that was not updated when room was
renovated.)
is the heat on if the T-stat is not calling for heat? Is the valve stuck? (No)
is the room too hot? Is the T-stat calling for heat? (No.)
NCAPPA
Multiple work orders from a new space
thatHVAC
waspresentation
just renovated having hot and cold
issues.
Seven Steps to Problem Solving
• 5th Why:
– Why is the dehumidification system still on?
Seven Steps to Problem Solving
is the dehumidification system still on? (The system was never
updated as an office space not needing the same humidification
schedule.)
is BAS running dehumidification cycle? (Room has a humidity set point that was not updated when room was
renovated.)
is the heat on if the T-stat is not calling for heat? Is the valve stuck? (No)
is the room too hot? Is the T-stat calling for heat? (No.)
NCAPPA
Multiple work orders from a new space
thatHVAC
waspresentation
just renovated having hot and cold
issues.
Action
•
•
Trending
Occupant Reports
Seven Steps to Problem Solving
• Countermeasure:
– Make sure when all projects are done that the new use
of the area is communicated to the controls
department.
Seven Steps to Problem Solving
Make sure when all projects are done that the new use of the
area is communicated to the controls department
is the dehumidification system still on? (The system was never updated as an office
space not needing the same humidification schedule.)
would the room need a humidity set point? (The room has a high humidity problem or the room was designed
for book storage).
is BAS running dehumidification cycle? (Room has a humidity set point that was not updated when room was
renovated.)
is the heat on if the T-stat is not calling for heat? Is the valve stuck? (No)
is the room too hot? Is the T-stat calling for heat? (No.)
NCAPPA
Multiple work orders from a new space
thatHVAC
waspresentation
just renovated having hot and cold
issues.
Seven Steps to Problem Solving
• 4. Implement the Process:
– a. Communicate the correction to everyone who needs to know.
– b. One point lessons are often good for this purpose.
– c. Don’t forget to inform other supervisors and other zones that could have the
same issues
• 5. Analyze Effectiveness:
– a. Review the results of the new procedure.
– b. Modify the new process if needed.
– c. You may even need to try something completely different if the new process
is not effective. In this case, you should also ask yourself if you really got to
the root cause.
Seven Steps to Problem Solving
• 6. Standardize:
–
–
–
–
–
a. Update your PM procedure to reflect the new trouble shooting process.
b. Update training plans for new technicians.
c. Ensure that everyone who needs to know is in the loop.
d. Ask yourself if there are other areas to apply this new knowledge.
c. You may have another building with the same issue that could be corrected by your
new process.
• 7. Check & Control:
– a. Implement systems to insure the new procedures are followed and are effective.
Follow up.
Tools and Testing Equipment
•
•
Temperature Meter
Humidity Meter
Thank You
Questions & Comments?