A homeowner in Newark called about a wall furnace that came with the house and had stopped doing its job. On cold mornings the room never really warmed up. Wall furnaces like this are everywhere in older Bay Area homes. They bolt into a stud bay, vent straight up through the roof, and pull combustion air from the room itself. Simple machines. But they age.
This one was past patching. The customer did not want another repair. He wanted the old unit gone and a new one in its place.
Why the old unit was done
When a wall furnace gets to thirty years, a few things go at once. The heat exchanger thins. The pilot and ignition system starts acting up. And the gas-side safety hardware on a unit that old will not pass current code the moment anything needs replacing. So even a “small” repair on a heater like this tends to snowball into code-required upgrades. Replacement was the right call here, and the cheaper one over a few winters.
The rule I use on these is simple. If the heat exchanger is suspect and the gas controls are obsolete, you are not repairing a heater anymore. You are rebuilding it around a tired core. Better to start fresh.
What went in
We installed a Williams Cosy wall furnace, 25,000 BTU, top-vent natural gas. The size was matched to the room volume the unit actually serves, not just bolted in because it fit the opening.
The rest of the work lived on the gas and vent side. The original gas valve was an old globe-style valve, which code no longer accepts, so we set a new accessible quarter-turn ball valve at the unit. We refit the vent connector so the draft lined up with the new furnace’s spec. Then we calibrated the thermostat to the new ignition logic so it fires clean and holds temperature.
The part that makes it stick
Pulling the old furnace and dropping a new one in is the easy half. The gas connection is where these jobs are won or lost. We make the connection with the new shutoff valve, soap-test every joint, and confirm draft on the venting before anything gets closed up.
This matters because a missed leak does not announce itself. It shows up months later as a carbon monoxide problem, or worse. I would rather spend the extra fifteen minutes on a soap test than catch a callback that involves a CO alarm.
What the homeowner ended up with
A new wall furnace that lights reliably on cold mornings and runs quiet, with the thermostat controlling it cleanly. Because we brought the gas shutoff up to current code as part of the swap, any future service on this unit will not stall on a “the valve has to be replaced first” delay. The equipment is covered by our 1-year ADRIUM warranty plus the Williams Furnace Company factory warranty on the unit itself.
If your wall heater is the original one that came with an older Newark or Tri-Valley home and it is losing the cold mornings, a replacement like this is straightforward when the gas-side work is handled correctly. You can see how we approach larger jobs through our HVAC division, and our furnace repair page covers what we check before recommending a swap.
