Flush the tank while it’s still young

Two jobs. The first is the flush: five separate conversations say drain the tank once a year to clear the mineral sediment that settles on the bottom, because sediment cuts efficiency, burns out elements, and in the worst case ruptures the tank; two conversations say a yearly flush roughly doubles a heater’s life. One account's two diagnostics: listen at the bottom of the tank while it heats — bubbling and popping is sediment boiling water trapped under it — or drain a cupful from the tap at the bottom and look at the colour and the grit. One account says sediment can add hundreds of pounds to a tank; one says the drain tap sits a few inches above the true bottom so a flush never gets everything, and another caution says a flush can push loosened grit into your taps and filters. One caution says if you have soft municipal water or a softener the sediment problem is much smaller and the schedule can relax. The second job is the anode rod, which four conversations describe and two more explain: a rod of magnesium or aluminium hanging inside the tank whose whole purpose is to rust so the steel tank does not. It is a bolt head on the top of the tank; gas heaters have one too. When it is gone the tank starts rusting, and one account says smelly or discoloured hot water is the sign. Four conversations say inspect it every few years — three to five is the common number, some say up to ten — and one account’s replacement rod cost twenty to forty dollars. The only way to know is to pull it and look. One account says the metal should match the water: magnesium for town water, aluminium for a well; one caution says a water softener changes a rod's life; two conversations mention powered anodes that last a decade and cure the sulphur smell. One correction is worth carrying: an account was told the anode is powered and minds being uncovered — it is not, it is a rod that rusts. And one open question the accounts raised and did not settle: one says never wrap the new rod’s threads in plastic tape because the rod only works if it is electrically joined to the tank, and the conversation left it there. Two conversations note that tankless heaters have no anode and need a yearly descale instead, and that some new electric tanks are plastic and need none.

Probably not — and this is the point where the people here disagree usefully, so both sides are here. Four separate conversations say maintenance on a very old heater is dangerous to the heater: a tank that has gone ten or fifteen or twenty-five years untouched may be held together by its own corrosion and crust, and opening a drain or a rod port can bring on the failure you were trying to prevent, with the flood that follows. Three contraindications say it in three ways, three cautions rated high say a neglected tank can disintegrate into rust when opened, and one caution says a first flush after six to nine years can halve the remaining life or end it. One account passes on a plumber’s advice: leave the old ones alone until they fail on their own. Against them, in one conversation three accounts to three: a rod inspection is worth doing even on a unit of six to twelve years, because a new heater costs well over a thousand and a rod costs a fraction, provided you are ready for the tank to fail while you are at it. Another exchange, three accounts to two, and a third, two to one, land the same way, and the accounts' own deciders overlap across all three: the age of the unit, your local water hardness, whether it has a drip pan and a leak alarm beneath it, and whether you have the money for a replacement this week if the tank lets go. This page’s reading of that: if the tank is young and has been flushed, flush it; if it is old and never touched, you are not maintaining it any more, you are waiting — so put a pan under it, put money aside, and let it be. One account in a multi-unit building adds the reason to decide rather than drift: a burst tank there is a claim against your insurance or the building’s, and neglect can be the reason it is denied. And one account notes that these things fail on weekends and holidays, when the labour costs double, which is the argument for replacing on your own schedule rather than the tank’s.

Power, water, cool, drain, refill, power — and the people here are firm about the two ends. Three separate conversations say the electricity or the gas goes off before anything else, and the reason is the element: run dry for a moment, an electric heating element burns out and, one caution rated high says, can break apart inside the tank, which usually means a new heater rather than a new element. Then the cold-water supply off, and a hot tap open somewhere in the house to let the pressure out. Then patience: one account says the whole job waits for the tank to cool, because what comes out of the drain is scalding. The people here argue a little about how much to drain. One exchange, two accounts to one, is between draining fully to get at the rod and leaving some water in so the tank’s own weight holds it still while you break the bolt loose; another, one to one, says you need not drain at all for a rod change — shut the supply and relieve the pressure — and this page leaves that to the accounts, noting that a tank that shifts while you are wrenching on it is its own hazard. Refill is the other end where people wreck heaters: two conversations and a contraindication say the tank must be completely full — a hot tap running steadily with no air — before the power goes back on. One account tests the pressure-relief valve after refilling, to be sure it opens and reseats, and says it must never be capped. One caution rated high is about the plumbing around the tank rather than the tank: old shut-off valves and fittings that have not moved in years can crumble in your hand, so know where the main shut-off is before you turn anything. And a line from the safety note repeated on purpose: if you cannot identify the shut-off and the drain with confidence, one contraindication says you are not the person for this job yet.

Expect that. Six cautions and seven accounts describe the same thing: a rod that has sat in a tank for years is seized, and a first removal wants a long-handled bar or an impact wrench, sometimes two people and something to brace the tank, and sometimes the rod has to be cut to come out because the ceiling is too low to lift it. One account says a standard bar and a tap with a hammer may not be enough in a tight space. The accounts’ methods: a penetrating oil on the threads — one caution names the household spray everyone reaches for and says it is not one — a long cheater bar for leverage, a helper on the tank. One account frees seized rods with a torch flame, and this page refuses to repeat that on a gas appliance in a house. For low ceilings, several accounts say segmented rods exist — jointed like sausage links — that go in and out of a short space. Two more contraindications for this stage: some heaters have the anode soldered into the cold-water inlet rather than on top, and one caution rated high says you cannot get that one out without cutting a pipe — a professional’s job; and not every heater has an accessible rod at all, so one caution says read the manual before you start unscrewing things. If you have wrestled it out and it is a thin wire with lumps on it, it was overdue; if it is still mostly rod, one account says put it back and check again in a couple of years.

The people here have a good answer to this, and it is neither. Two separate conversations say hire a professional once, watch them do the whole job on your tank, and film it — then decide whether next year’s is yours. That handles the two readers this page is not for. Gas: one contraindication says do not work on a gas-fed unit unless you know gas-line safety, and one exchange, two accounts each way, is exactly that argument — it is easy with a video and the fear is overblown, against gas connections and local inspections make a professional the prudent choice; the accounts’ decider is gas or electric, your local rules, and your honest comfort. The gas safety part — the small sensor that shuts the gas if the flame goes out — is the other line: one account cleans and reuses theirs for years, two say it is a safety-critical part that is replaced, not scrubbed, and a contraindication agrees, and so does this page. Tenants: one contraindication says if your lease forbids it, it is not yours to do, and a caution says a landlord who is asked too often may start blaming the tenant. Beginners: if you cannot find the shut-off and the drain, see the previous answer. One account keeps a binder of service dates and receipts, for the warranty and for the next owner, which is the cheapest part of the whole job. One account rents their heater and lets the supplier own the problem. And one account, with hard water and an aging unit, decided the honest answer was to skip the maintenance and replace the heater themselves — which, for the reader whose tank is old and untouched, is the same conclusion the previous answer reached by a longer road.