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The Case of the Haunted Boiler Room, this weeks case on Boiler Room Detective

RayWohlfarth Member Posts: 1,155
This was a strange service call. The owner called and said the building got cold each night and warmed in the morning. The building had two low pressure on off steam boilers with three zone valves. Each zone valve was controlled by a non programmable Honeywell T87 thermostat inside a clear plastic lock box. We placed a temperature data logger there for a few days and saw the temperature did start dropping around 11pm and started to climb around 6am. The onsite maintenance tech believed the building was haunted and blamed the ghost for the problem. The problem just started a week or so before.
Can you solve the case Detective?
Just like last week, I won't give any more clues or tell what I found until Friday when the video is released.

Ray Wohlfarth
Boiler Lessons


  • retiredguy
    retiredguy Member Posts: 722
    edited March 8
    Someone who did not like a warm night temperature would remove the cover, which was easy to do, by squeezing the sides and lifting the cover, and changed the settings. Also, you can fashion a tool to poke through the side vent holes to change the settings. (Have done both) They may have also found a key and with those boxes all the locks took the same keys.
  • ratio
    ratio Member Posts: 3,377
    Since it seems to be holding 60° at night, I'd look for an old night controls that may have inadvertently been reactivated.
  • unclejohn
    unclejohn Member Posts: 1,810
    I have seen a dimmer switch replace a regular on iff toggle switch and cause tstat problems but you would show that in the photo right. 
  • retiredguy
    retiredguy Member Posts: 722
    There was a case in the Shadyside area of Pittsburgh where one of the tenants had a fight with his wife who threw him out of their apartment. So, he would sneak into the boiler room at night (unlocked door) to sleep since he said he had no other place to go, and turn off the boilers. In the morning, he would get up, turn the boilers back on and go about his normal routine. Could this be the same?
  • Steamhead
    Steamhead Member Posts: 15,891
    ratio said:

    Since it seems to be holding 60° at night, I'd look for an old night controls that may have inadvertently been reactivated.

    I agree. I've seen plenty of these that "had been disconnected/bypassed" but were apparently still active.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    EBEBRATT-Ed Member Posts: 13,347
    Someone thought the boiler emergency switch was a light switch. Off at night on in the morning.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 5,365
    edited March 9
    What is going on behind the wall? I had a customer, a restaurant, that had a problem with maintaining the set point of the thermostat. Turns out that the large exhaust fan in the kitchen put the building in a negative pressure condition. Some of that air pressure was relieved by air leaking thru the wall at the thermostat location. Outside air was leaking in thru the roof and down the wall cavity. That cold air in the winter affected the temperature in the thermostat as it infiltrated past the thermostat into the restaurant.

    I had another customer that installed the thermostat for the first floor on the wall where the second floor zone radiator supply pipe was located. If the second floor was calling for heat, the wall would get some radiant heat from the pipe in the wall. That would affect the first floor zone thermostat. It took me 3 years and 4 thermostats to figure this out.

    Could there be hot boiler room air leaking in through the wall, or could the room on the other side of that wall be affecting the wall temperature? Is there a bakery in the building? Cooking baked goods through the night in order to have Fresh Doughnuts for the morning shift at the Police Precinct across the street could explain this. Whatever is happening, it must stop every morning at about 6 AM
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Dave338
    Dave338 Member Posts: 3
    Could there be a light under the T-stat that they turn on at night to illuminate a hallway or the area near the T-stat?
    I used to use a light to fool a fixed thermostat in Military Housing. Place a little table with a little lamp on it in the hall under the thermostat. That would keep the T-stat just warm enough to keep the AC running so the house would stay a little cooler than the T-stat setting. In winter, first thing in the morning I'd pull one of those Freeze Pops out of the freezer and lay it on top of the T-stat to bring the heat on.
  • scott w.
    scott w. Member Posts: 190
    edited March 9
    In the 70's during the energy crisis the school district lowered the temps of the thermostats in the building. If you had a class at the far end of the building in the corner classroom they were always freezing cold. To get the temp up we would put a cold wet paper towel on the thermostat. It was a little rectangle box with no controls. That always worked. 1. A person is manipulating the thermostat or 2. There is another heat source near the thermostat. Always dislike waiting in suspense for a week for the mystery to be resolved. Will be surprised if the answer isn't already in one of the posts above. Looks like almost all possible situations have been covered.
  • mattmia2
    mattmia2 Member Posts: 7,375

    Also, you can fashion a tool to poke through the side vent holes to change the settings.

    I use the blade of my pocket knife. Works especially well on the ones with a dial on the bottom.
  • Ogg
    Ogg Member Posts: 9
    The ghost in my house is only active during the day, but I still doubt the ghost story. Given the short time frame, but with the verified results, it has to be a new human activity. 
  • PDTech
    PDTech Member Posts: 1
    Just one zone, or all 3 with lower temperatures?
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,155
    Well @retiredguy was the first with the correct answer Congrats! As a prize, you get unlimited knowledge for the next 24 hours. :)
    An HVAC tech was staying at the rehab facility and liked it cooler when sleeping. He had a key for the thermostat lock box and would turn down the heat before bed and turn it up when he woke. I think you may find it interesting to see how we determined the cause.
    Thanks Detectives. Until next week. here is the link for the video

    Ray Wohlfarth
    Boiler Lessons
    Erin Holohan HaskellSolid_Fuel_Man
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,029
    Thanks for sharing these mysteries with us, @RayWohlfarth!
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,155
    thanks Erin Im having fun
    Ray Wohlfarth
    Boiler Lessons
    Solid_Fuel_ManErin Holohan Haskell
  • retiredguy
    retiredguy Member Posts: 722
    edited March 10
    Thanks for the good comment @Ray, but can I exchange the unlimited knowledge for a double cheese burger. God bless
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,155
    You got it Have a great weekend 
    Ray Wohlfarth
    Boiler Lessons
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,571
    Love it Ray! These are fun!
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,155
    Thanks @Solid_Fuel_Man I appreciate it
    Ray Wohlfarth
    Boiler Lessons
  • SteamFTW
    SteamFTW Member Posts: 52
    @RayWohlfarth The best thing about these "puzzles" isn't necessarily getting the right answer. It's the questions that we're all prompted to ask. The most powerful tool each of us possesses is between our ears, and these are great for keeping that tool sharp. Thank you very much for sharing.
    CLambErin Holohan Haskell
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,155
    @SteamFTW I agree @DanHolohan always says we shouldn't troubleshoot on the drive there but most of us do that Sorry Dan Im to the age where I want to stimulate that side of the rain. Thanks for the comment

    Ray Wohlfarth
    Boiler Lessons