Free template · updated November 3, 2026
Tankless water heater instructions for guests (template)
A tankless heater never runs out of hot water, but guests still message about it. The water takes a few seconds to heat, a tap on a trickle may stay cold, and two showers plus the dishwasher at once can make the water lukewarm.
This template explains how it works in plain words, a couple of habits that help, and what to do if a code appears on the display. Fill in your model's display location and settings.
The template
Replace anything in [brackets] with your own details.
How it works
- This home has a tankless water heater. It heats water as it flows, so it won't run out the way a tank can.
- When you turn on a hot tap, it takes [Number] seconds for hot water to arrive.
Getting good hot water
- Please turn the tap on at least half way. On a trickle, the heater may not switch on and the water stays cold.
- Running two showers and the dishwasher or washer at the same time can make the water cooler. Spacing them out helps.
- If the water goes cold for a moment and then hot again in the shower, that's normal when someone turns another tap on or off.
Temperature
- The heater is set to [Temperature setting]. Please test the water before getting into the shower or bathing children.
- Please leave the setting on [Display or control location] as it is.
Where it is
- The heater is at [Location, e.g. on the wall in the utility room / outside wall by the deck].
- [Gas model: it has a vent outside at [Vent location]; please keep it clear of snow, furniture and barbecues].
Safety
- [Gas model: if you smell gas, leave the building without touching switches, and call [Gas company emergency number] from outside].
- Carbon monoxide alarm: [Alarm location].
If something goes wrong
- No hot water at all: check the display for a code and turn the hot tap on fully. [Reset step, e.g. press the power button off and on once].
- A code shows on the display: please send us a photo of it at [Host phone].
- During a power cut, the heater won't work, even on gas, as it needs electricity to run.
- Still not working: text [Host name] at [Host phone]. Please don't open the cover.
Copied. Paste it into your welcome book or message.
Tips
- Tell guests to open the tap more than a trickle; it fixes many 'no hot water' complaints.
- Ask for a photo of any error code so you can diagnose it remotely.
- Keep outdoor vents clear of snow and say so if guests might stack things nearby.
- Descale or flush the unit on the schedule in its manual, especially with hard water.
- Mention that it needs power even on gas; many guests assume it won't.
Put it on one guest page instead of a binder
Keegix turns your welcome book into one link and a QR sign by the door. Upload the binder you already have and AI drafts the page in about a minute, or paste this template in. Free forever for one property.
Questions
Why does a tankless water heater go cold for a few seconds?
The heater needs a moment to fire up when flow starts or changes, so a short cold burst can happen. It usually settles quickly.
Can a tankless water heater run out of hot water?
Not in the way a tank does, but it has a maximum flow. Too many taps at once can make the water cooler.
Does a gas tankless water heater work in a power outage?
Most don't, because the fan and controls need electricity. Check your model's manual.
More free templates
- Water heater instructions for guests (template)House manual instructions
- Water softener instructions for guests (template)House manual instructions
- Power outage instructions for guests (template)House manual instructions
- Dishwasher instructions for guests (template)House manual instructions
- Vacation rental welcome book templateWelcome book templates
- Power outage instructions for guests (template)House manual instructions
- Emergency info for guests in Canada (rental template)Emergency info by country
All house manual instructions · Every free template
Free to use
Copy it, change it, print it, use it with any platform. Sharing it with a host group, on a blog or in a forum? A link back to this page helps other hosts find the latest version:
https://keegix.com/house-manual/tankless-water-heater/