How to Get Hot Water Without a Boiler While It Is Fixed

First, check whether you have a cylinder

Everything depends on this. Look for a large insulated tank, usually in an airing cupboard on the landing or in a bathroom. If you find one, you have stored hot water and almost certainly an immersion heater, which makes this easy. If you have no tank and the boiler is on a kitchen wall with pipes going straight to the taps, you have a combi, and there is no backup built into the system.

Not sure what the cupboard is? Our guide on what is an airing cupboard shows what the cylinder and its parts look like.

If you have a cylinder: use the immersion heater

The immersion heater is an electric element inside the cylinder, fitted precisely so you still have hot water when the boiler is off. Look for a switch on the wall near the cylinder, often marked "water heater" and sometimes with a red neon light. Switch it on. If there are two switches, marked Bath and Sink, Bath heats the whole tank and Sink heats the top part, which is quicker when you only need a wash.

From cold, a typical tank takes around one and a half to two and a half hours to heat, depending on its size. Our guide on how to turn on an immersion heater covers timers, dual switches and what to do if nothing happens.

• Leave it on only as long as you need it, or put it on its timer. An immersion heater costs more per litre than a gas boiler, so it is a stopgap, not a new normal.
• If the switch light comes on but the water stays cold after three hours, the element or its thermostat may have failed. Our page on an immersion heater not working walks through the checks.
• If the switch trips the fuse board as soon as you turn it on, leave it off. Our guide on an immersion heater that keeps tripping explains why.

If you have a combi boiler: what still works

An electric shower is the best news if you have one. It is the box on the wall with its own pull cord or isolator switch, and it heats cold mains water itself, so it works whether the boiler does or not. A mixer shower or a power shower does not heat anything and will run cold.

For washing up and a strip wash, a kettle is your friend. A full kettle holds about one and a half to one and three quarter litres, and three or four kettles mixed with cold in a bowl or a shallow bath is enough to wash. Large pans on the hob add more. It is slow, but it works.

Kettle water scalds in a fraction of a second. Always put the cold water in the bath or bowl first and add the hot to it, never the other way round, and test the temperature with your elbow before a child or older person gets in. Keep children out of the bathroom while you carry boiling water.

Longer outages: temporary hot water options

If the repair is waiting on a part for several days, a few things help.

• A plug-in instant water heater or a small undersink electric water heater can be fitted to one tap as a temporary measure. They need a proper connection to the water supply and a suitable electrical supply, so this is a job for an engineer, not a quick plug-in.
• A thermostatic electric shower can be fitted if you do not have one and the boiler will be out for a long time, though that is usually worth it only if you would want one anyway.
• Showers at a gym, a leisure centre, work or a friend nearby will often cover a few days more easily than any appliance.
• For landlords with tenants in the property, temporary electric heaters and a plan for hot water are part of meeting your repair duties. Our guide on landlord hot water responsibilities sets out what is expected.

What not to do

A broken boiler in cold weather tempts people into shortcuts. A few are genuinely dangerous.

• Do not keep pressing reset on a boiler that locks out straight away. One reset is fine. Repeated resets on a boiler with an ignition or flue fault can make things worse.
• Do not use a camping stove, a patio gas heater or a barbecue indoors to heat water or rooms. They produce carbon monoxide and are made for outdoor use.
• Do not try to wire an immersion heater into a plug socket, or run one from an extension lead. A standard element draws close to the limit of a plug in normal use and needs its own circuit.
• Do not take the boiler casing off or try to bypass a fault. Gas work must be done by a Gas Safe registered engineer.

Keeping warm while the heating is off

If the boiler runs your radiators as well as your hot water, you have lost both. Electric oil filled radiators and convector heaters are the safe stopgap, used in the rooms you actually sit in, with the doors shut. Put anyone vulnerable in the warmest room. In a hard freeze, keep a little heat in rooms with pipes on outside walls, and know where your stopcock is in case a pipe does freeze and split.

Getting the boiler fixed quickly

Engineers can fix things faster when they know what to bring. Before you call, note the boiler make and model from the front panel or the data badge, any fault code on the display, the boiler pressure gauge reading, and what happened just before it stopped. Our guide on is no hot water an emergency helps you judge how urgent it really is.

We diagnose boilers and repair cylinders, immersion heaters and the valves between them across London, with 20 engineers who carry the common parts. Call 020 4652 5111 or send an enquiry and we will tell you honestly whether it is a same day fix or a part to order. Our rate is on the pricing page and agreed before we attend.