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Hamilton CSD Water Heater Installation 2026

Highland Elementary School in Hamilton, Ohio runs on two domestic water heaters, and an elementary building cannot go a day without hot water — handwashing, the kitchen and custodial work all stop at once. Hamilton City School District asked for a plan to replace both units on its own schedule instead of waiting for the units to set one. What follows is that proposed scope; it describes work as proposed, not work performed.

The proposal replaces both heaters with two high-efficiency condensing natural gas units at 199,000 BTU/hr each, on 120 volt single phase power. Hot and cold water piping is modified and reconnected, all new and modified piping is insulated, and the flue and combustion air piping is reworked, because a condensing heater does not vent the way the unit it replaces did. Gas piping is modified and a gas regulator provided for each heater. The existing housekeeping pad is reused. Both units are filled and flushed, and the old heaters and the debris leave with the crew.

The electrical scope is deliberately small. The two existing 20-amp receptacles come out, conduit and conductors are modified to land on the new units, and the existing 120-volt 20-amp circuits and wall-mounted disconnects are reused. No controls work is required.

What the district would end up with is the same two-unit arrangement it has today, in condensing equipment carrying a three-year heat exchanger and tank warranty from the manufacturer, and a hot water plant where one unit out of service is a service call rather than a closed building. Pricing is against a pre-bid TOP-C unit price contract.

Hamilton CSD Water Heater Installation 2026 — photo 1

Hamilton CSD Water Heater Installation 2026 — photo 2

Hamilton CSD Water Heater Installation 2026 — photo 3

Technical Discussion

Two water heaters instead of one

The obvious way to replace two water heaters is with one larger one. Fewer connections, one vent, one regulator, one thing to service. In plenty of buildings that is the right answer. In an elementary school it is not, and the reason is what the building does on the day that unit is down.

A school cannot operate without hot water. Handwashing at that age is not optional, the kitchen has health requirements that do not bend for a lead time, and custodial work stops. Put the building on one heater and all of that depends on one heat exchanger, one gas valve and one control board. Two units at 199,000 BTU/hr each means a failure takes half the capacity rather than all of it, and the school stays open while the part is on its way.

Comparison of one large water heater and two 199,000 BTU per hour heaters when a single unit fails. One heater leaves zero capacity. Two heaters leave 50 percent, enough to keep the school open. — Figure 1 — Redundancy is the reason the replacement stayed at two units.

The second argument shows up on the gas bill rather than in a crisis. Domestic hot water demand in a school is not steady — it spikes around meal service and cleanup and sits near nothing for most of the day. A single unit sized for the spike spends most of its life cycling on and off at a fraction of its capacity, and short cycling is where condensing equipment gives back the efficiency it was bought for. Two smaller units sharing the load each run closer to their useful range at ordinary demand. Worth stating plainly: no controls work is in this scope and no new sequencing is proposed.

The third reason is the least interesting and often the one that settles it. The building already has two heaters, two circuits, two disconnects and a housekeeping pad built for two. Staying at two keeps the electrical scope to modifying conduit and conductors and reusing the existing 20-amp circuits, and keeps the pad where it is. One large unit would likely mean resized gas piping, a different vent path and a pad rebuilt to suit it. The replacement that fits the room it is going into is the one that gets done over a summer.

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