The quote, already started
⚠️ These are starting numbers, not market rates. Put your own in.
What the job actually is
- Find out what is there now: type, capacity, age, fuel, and whether it failed or is just old.
- Size the replacement for the household rather than copying the old label.
- Check the location — clearances, the base, access to get the old one out and the new one in.
- Check where the relief valve and tundish discharge, and whether that still complies.
- Check the electrical or the gas supply, and whether the existing one suits the new unit.
- Isolate, drain the old unit down, and disconnect it.
- Get the old one out. On a second storey or in a roof space this is the hard part of the day.
- Set the new unit, level, on a suitable base, with the clearances it needs.
- Connect water, relief line and tundish, plus the electrical or gas as applicable.
- Fill, purge, commission, check for leaks, and issue the compliance certificate your state requires.
Materials
- The unit — type, capacity, fuel and brand, and whose warranty it carries. The hot water sizing calculator gives storage size or continuous flow rate for a household.
- Tempering valve, which is a requirement rather than an option on most installations.
- Relief valves, tundish and drain line to a legal discharge point.
- Isolation valves, non-return, flexible connections and unions.
- Pipework and fittings, sized for the flow — the water pipe sizing calculator takes loading units to a flow rate to a pipe size with a velocity check.
- A base or stand, and seismic or securing straps where they are required.
- Electrical or gas connection materials, depending on the unit.
Size it for the household, not for the sticker on the old one. The unit being replaced may have been undersized for years — which is exactly why the family runs out of hot water every winter — or oversized and costing them to keep. The sizing calculator is a starting point from occupancy and usage; the conversation with the customer about how many showers happen at 7am is the rest of it.
What the price assumes
- The replacement goes in the same location, and that location still complies.
- The existing relief and tundish discharge is legal and usable.
- The existing electrical circuit or gas supply suits the new unit.
- The old unit can be removed by one person along the route you looked at.
- The base is sound and no new one is needed.
- Water pressure and the existing pipework suit the unit being installed.
- No asbestos in or around the enclosure, and no structural work required.
Extras that come up
- Relocating the unit, because the old spot no longer complies or no longer fits.
- A new relief and tundish drain run to a legal discharge point.
- Electrical work — a new circuit, a switchboard that is full, or a changeover from off-peak.
- Gas work — an undersized line, or a meter that cannot carry the new unit.
- A pressure limiting valve, or an expansion control valve the old install never had.
- Removal and disposal of the old unit, which is heavy and full of water.
- Difficult access — a roof space, a second storey, or a cupboard the new unit will not fit through.
- Making good a base, a floor or a wall that the old unit was quietly leaking onto.
Things nobody charges for, and should
- Draining the old unit down, which is not fast on a large storage system.
- Getting it out, which on anything but a ground-floor external install is most of the physical work.
- Disposal, which the tip or the scrap yard charges for.
- Commissioning and the leak check, which is time standing there watching joints.
- The compliance certificate and the paperwork, which is real administrative time after you leave.
- The callout and travel, on a job that is usually urgent and rarely nearby.
- Telling the household the water is off, and the wait while the new one heats.
A worked example
A failed 250 L electric storage unit on a ground-floor external slab, replaced like-for-like in the same location, existing relief and tundish discharge legal and reusable, existing circuit suitable, new tempering valve, old unit removed and taken away. Plumber registered for GST.
| Line | Qty | Rate | Total |
|---|---|---|---|
| Attend, assess and isolate | 1 job | $180.00 | $180.00 |
| Supply 250L electric storage unit, incl. warranty | 1 ea | $1,480.00 | $1,480.00 |
| Drain down, disconnect and remove old unit | 1 job | $340.00 | $340.00 |
| Set new unit, connect water and relief line | 1 job | $620.00 | $620.00 |
| Supply and install tempering valve | 1 ea | $290.00 | $290.00 |
| Fill, purge, commission and leak check | 1 job | $210.00 | $210.00 |
| Compliance certificate and disposal of old unit | 1 job | $195.00 | $195.00 |
| Subtotal | $3,315.00 | ||
| GST (10%) | $331.50 | ||
| Total inc GST | $3,646.50 | ||
| Deposit (30%) | $1,093.95 | ||
| Balance on completion | $2,552.55 |
These are starting numbers, not market rates. Put your own in. Every figure above comes from the line items in the builder at the top of this page.
Start this quote in Yamate — the lines, not the prices →The app fills in the same line descriptions and leaves every amount blank for you. Your prices, not ours.
Yamate keeps your rates and your standard lines, so the next one of these is a few taps rather than a blank page — then turns the accepted quote into the invoice without retyping it.
FAQ
What size hot water system does a house need?
It depends on how many people live there and when they all want hot water, not on what the old unit said. The hot water sizing calculator gives a storage size or a continuous flow rate for a household as a starting point, and the conversation about the 7am rush is the rest of it.
Why is a hot water replacement not just a swap?
Because the old one went in under different rules. Clearances, the relief and tundish discharge, tempering, the base and the electrical or gas supply all have to suit the new unit and the current requirements — and on an older install at least one of them usually does not.
Should the compliance certificate be a line on the quote?
Yes. It is a requirement rather than an extra, it has real administrative time behind it, and showing it makes the comparison honest against a quote that quietly left it out.
Should I take a deposit for a hot water job?
Usually yes, and often a larger one than other trades — the unit is a substantial cost you pay before it goes in. Put it on the quote as a percentage and check your state's rules on deposit limits.
Work out the materials first
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General information for licensed Australian plumbers, not legal, technical or financial advice, and not instructions for doing plumbing or gasfitting work. The rates on this page are starting points rather than market prices, and every figure is an estimate based on what you type in. Licensing, tempering, relief discharge and certification requirements are set by each state and territory — check yours before relying on this page.