Here’s my inspection protocol for the boiler portion of the inspection of hot-water systems, put together from various sources.
I welcome any comments, corrections or suggestions:
Check for Sight glass and/or low water cutoff: If so steam, conversion, or hybrid system.
**Describe as Open or Closed System: **Closed (forced) system will have circulation pump.
Observe piping: Closed system with over-sized pipes pitched toward boiler usually means a conversion from older open system, may be missing safety devices.
Observe Expansion tank:** If open system: **3" above highest point of system and vented
**Observe Pressure Relief Valve:**30 psi , piped to w/I 6" of floor
Watch for plugged valve
Must be on boiler side of devices such as pressure reducing valves.
**Observe High Temp Switch:**Hi Limit: Typically 210F. If higher, suggest service. Above 250F is likely safety hazard.
Lo Limit: Typically 110-130F
**Observe Backflow Preventor:**Observe location: Should be on cold water supply upstream of pressure regulator.
Observe Directional Marking: Should point toward boiler
Observe If Pressure Reducing Valve Installed: PRV (AKA auto make up valve or feed water pressure regulator) is not required, it is a convenience.
**If Closed System:**Observe Circulation pumps(s):
Past or present leaks
**Observe drain valve: **Missing or closed is defect – often modification of older open system
**Observe Evidence of past/recent repairs. **Service tags?
Observe Draft Diverter/Hood: Check inside for corrosion, scorching, and back-drafting
Observe Piping Material.
Observe Piping Type:- Two Pipe (AKA Loop): circa per 1950 large diameter pipes, two runs each with capped end.
- One Pipe Monoflow: circa 1950+, 1-1/4" iron or copper pipe,
- Mainless loop systems: circa 1960+ , baseboard, zoned groups in series. (ex: loop, monoflow, mainless)
Observe Piping Insulation: Possible asbestos?
Observe Boiler: cast or welded (cast iron will not have welds at pipe connections).
**Observe at least one cycle:**Record: thermostat settings
Observe and Record Temp/ Pressure: At start and after running 15 min:[INDENT]Start ___ / ___
Run ___ / ___
Off ___ / ___
Normally 12 psi cold, 16-22 psi hot, and 160-200F
18psi+ and/or 200F+ requires HVAC inspect.
More than 5 psi rise may mean waterlogged expansion tank
Observe Relief Valve, **do not operate: **Check for leaks
**Observe Drain valve, do not operate: **Check for leaks
Observe Circulation pump: Check for operation / leaks
**If copper tube boiler:****Observe operation of pump: **pushing water through tubes when burner is on.
Observe Burner pattern
Observe Operating Sound - Any unusual noises during operation?
**After burner shutdown:**Observe any dripping water: from heat exchanger (indicates leak)
Observe any steam: (indicates leak)
**Listen for hiss: of evaporating water from leaks (indicates leak)
** Restore thermostat settings[/INDENT]