York’s history goes back to 1874, and the brand, now part of Johnson Controls, covers residential air conditioners, gas furnaces and heat pumps as well as commercial rooftop and split equipment. We work on all of it in Novato, San Rafael and the rest of our Marin service area. At home, two York problems come up often: coils icing over and rooms that will not hold an even temperature. On commercial buildings, the usual call is about rooftop units that have stopped keeping a shop or office comfortable.
Ice on the coils: what it tells us
Ice on a York indoor coil, or frost creeping along the copper line to the outdoor unit, is a symptom rather than a failure. The coil is running below freezing, and there are two main reasons:
- Not enough air across the coil. A clogged filter, a dirty coil, a slow or failing blower motor, closed registers or a blocked return. This is the more common cause.
- Not enough refrigerant. A leak lowers the pressure, and the coil temperature drops with it.
What to do: switch the thermostat from Cool to Off, set the fan to On so the ice melts, and replace the filter if it is dirty. Do not chip at the ice. If the coil ices again once cooling restarts, call. We check airflow first, then measure the refrigerant charge and search for a leak if it is low; adding refrigerant without finding the leak is not a repair. Our frozen AC coils page has more detail.
Rooms that will not hold a temperature
Inconsistent heating or cooling in a York system usually starts with the simple things:
- The filter. A dirty filter is the most common reason airflow drops and some rooms fall behind.
- The thermostat. A thermostat in the sun, near a supply register or with a wrong setting satisfies itself while the rest of the house drifts.
- The ducts. Leaks, crushed runs and disconnected boots in the crawlspace or attic starve individual rooms.
- The equipment. Only then do we look at blower speed, refrigerant charge or furnace output.
If one or two rooms are the problem, our page on uneven temperatures explains what usually causes it and what fixes it.
York furnaces and heat pumps
On a York gas furnace, a no-heat call follows the ignition sequence: inducer, pressure switch, igniter, gas valve and flame sensor, then the limit switches and the blower. The control board’s flash code narrows the search. On a York heat pump, we add the defrost control, the reversing valve and any backup heat to the cooling checks. More on furnace repair and AC repair.
York commercial equipment
York’s commercial line includes packaged rooftop units, and they bring their own checklist: belt-driven or direct-drive blowers, economizers that bring in outdoor air when it is cool enough, gas heat sections, roof curbs and condensate drains that run across the roof. A stuck economizer damper, a slipping or broken blower belt or a clogged filter bank can make a rooftop unit look like it has failed when the compressor is fine. Shops, offices and other businesses can call our commercial HVAC service.
How we work
We are independent and not affiliated with York or Johnson Controls. After the diagnosis you get an itemized price, with no hidden fees, and we recommend only the repairs you need. Parts are factory certified and carry the manufacturer’s warranty, and our work carries a labor warranty.
Local notes
Inland Novato and the north side of San Rafael get noticeably hotter summer afternoons than the towns near the water, and that is when a York AC with a dirty filter or coil is most likely to ice up. A yearly maintenance visit before summer keeps the coil clean and the charge checked, and maintenance plans add priority scheduling and repair discounts.