Popping and rumbling is usually sediment — not urgent, but a sign of aging. Hissing can mean a leak. Water pooling at the base or a dripping relief valve is the one that needs a call now.
Popping or rumbling — sediment
Most common call we get. Sediment settles at the bottom of the tank, water gets trapped underneath it, and it boils up through — that is the pop. It is not dangerous, but it means the heater is working harder and the tank is aging faster. A flush usually helps; on an old tank it is a sign to plan for replacement.
Hissing or sizzling — possible leak
Water hitting something hot. Could be minor condensation on a cold day — or a leak dripping onto a fitting. Look under and around the tank. If you see water or rust streaks, that is worth a call before the tank lets go completely.
Banging in the pipes — water hammer
A loud knock when a faucet or machine shuts off is pressure slamming through the lines. Not a heater problem directly, but it beats up valves and joints over time. Arrestors or pressure adjustment fix it.
Ticking on a tankless unit
Normal expansion noise most of the time. If it comes with fluctuating water temperature or error codes, the heat exchanger probably needs descaling — especially in hard-water areas, and most of Bucks and Montgomery County qualifies.
Water pooling under the tank, or the temperature/pressure relief valve dripping and hot. Call or text (267) 227-8115 — a failing relief valve or a split tank does not wait politely.