United Mechanical Services, Inc.
United Mechanical Services, Inc.

Water Leaking?

If this is equipment we recently installed, please go no further, and call our office ASAP: 425.885.9100

If this is from equipment we have not installed or worked on we suggest you call us as well to get a service technician dispatched. If you would like to locate the source to identify the severity of the leak, follow these steps. (We do not suggest fixing the leak yourself unless you are familiar with the varoius types of equipment for doing so.)

Water leak sources can be very tricky to locate

One thing for sure, it travels downhill. Things like winds can affect this but can be eliminated if it's reasonably calm outside. Water can travel long distances at very little grade and these sources are hard to locate. Roof leaks can be due to poor construction methods, materials or damage from falling or flying debris. These are best left to a roofing professional to locate and correct and will not be covered here. We will be covering only HVAC related leaks. Water can also pool up in pocket areas or in materials such as insulation and continue to drip or flow long after the source has stopped.

As far as HVAC equipment is concerned, water can come from a few sources:

  1. Improperly installed or maintained drain lines or unlevel equipment.
  2. Improperly installed equipment which penetrated the structure, roof or wall.
  3. Incorrectly set or calibrated thermostat settings, air conditioning equipment.
  4. Air flow restrictions, poorly maintained equipment - dirty filter or trimming down air flow rates by closing or blocking registers and diffusers.

Methods of leak location

Unfortunately there are not many. The best leak detectors you have is 3 of your 5 built in senses. Sight, Touch and Hearing. We definitely do not suggest tasting it and smelling may help if its a sewage leak but otherwise may not be much more help.

Visually inspect where the water is coming from. Try to determine the basic area of the leak then attempt to classify the type of leak. Is it dripping from piping, equipment, structure or ductwork. Although it may be evident what it is dripping from it may be originating somewhere else and running to that point. Follow the next to determine the source.

Is it dripping from:

Ductwork? If so, determine as best as you can if it is coming from the inside of the duct (in which case it more than likely will be showing at seams or corners) or outside the duct. If it is inside, likely causes are clogged filter, airflow reduction, low thermostat setting or equipment out of level and causing drain pan inside to overflow. Clogged drain line could also cause this but possibly would show elsewhere as well. If it is outside the duct and it is raining outside, then the leak may be structure related.

Plastic Piping? If so, is this a drain line? If this is a supply line (copper) is it HVAC or Plumbing related. If it is a drain line, is it PVC - plastic and white in color or is it ABS - plastic and black in color. For the most part Air Conditioning companies use PVC for their drain lines. Some may use copper as well. If PVC is used (we use schedule 40) is it supported at least every 5 ft of distance and does it have at least 1/4" per foot of grade, 1" every 8ft. If so there should be no problem with drainage unless it is clogged. Various methods are available for clearing the clog. If the piping is plastic and black in color, then it is most likely a plumbing waste or drain line and should be checked by a qualified licensed plumbing firm.

Copper Piping? HVAC companies use copper piping for drain lines and also for hydronic supply and return lines. These hydronic lines are under pressure and should not be tampered with. Plumbers also use copper piping and the same applies. Refrigerant lines are also ran in copper and insulated. If oil or refrigerant is leaking, Stop and Call a Professional. Refrigerant is damaging to the Earth's ozone layer and we more than likely can recover the remaining refrigerant with our specialized equipment, repair the leak and get you back to a comfortable condition without much downtime.

Structure? If so is it raining outside? If not or has not then the problem is possibly the equipment which penetrates the structure and one of the other conditions described above applies.

Remember to call us if you need maintenance or repair on your equipment which by design should help in eliminating future HVAC related water leaks. Please do not use our online form for water leaks as they cause damage and therefore are a priority type of service call.

8901 Willows Rd. Redmond, WA, 98052 • Phone (425) 885-9100 • Fax (425) 881-6487
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