Gas boiler operation during a power outage: what will happen to the equipment in the event of a power outage

Vasily Borutsky
Checked by a specialist: Vasily Borutsky
Author: Maria Govorukhina
Last update: August 2019

To endure for some time without household appliances and a TV is quite real. The situation is much more serious if the gas boiler is interrupted during a power outage, even for a short time. It is especially unpleasant if the start of the power supply is delayed for an indefinite period. Do you agree?

On the forums, many masters argue that when the power is cut off with the gas equipment turned off in time, the boiler may break. Even worse, if carbon monoxide, which is life threatening, enters the room. Are you ready to take such a risk or is it better to abandon an electrically dependent heating source?

We will not let you freeze or empty your pockets, spending money on useless events. We will talk in detail about what will happen to the gas boiler if the power supply is suddenly cut off. You will learn how to ensure the smooth operation of even the most expensive electronic unit full of electronics.

What elements of the boiler depend on electricity?

Power outages not only in the hinterlands, but also in cities occur quite often. They happen due to emergencies, scheduled repairs and maintenance, breakdowns on the line. And the most unpleasant thing is that when the power is turned off, the operation of the gas boiler is paralyzed if it is of a volatile type.

The non-volatile gas boiler continues to function normally, even if a shutdown occurs on the power line. The only exception if working in conjunction with it pump, and the system of gravitational circulation of the coolant is not provided.

Non-volatile boiler device
Non-volatile boilers have the simplest, basic set of functions. They are less comfortable in operation than their volatile counterparts. But their work is absolutely independent of the supply of energy to the home power grid, moreover, they are less likely to fail

In a heating circuit with a simple boiler, the set of basic elements is approximately the following:

  • natural draft smoke exhaust system;
  • heat exchanger;
  • gas burner with nozzles for supplying gas, which is located in the combustion chamber;
  • gas supply and ignition unit;
  • expansion tank;
  • mechanical temperature sensor;
  • a control module, which includes a boiler ignition system (mechanical or piezo), temperature control;
  • security group (safety valve, pressure gauge, air vent).

Volatile devices are more complicated in the device. But is electricity really necessary and important for the functioning of a gas boiler?

Depending on the model and brand, in addition to the same basic set of elements, in some cases, electronic and automatic types, they may include such functions as:

  • forced ventilation system;
  • built-in circulation pump;
  • electronic system control module;
  • shut-off and control valves on an electric drive;
  • various sensors - water flow, temperature, flame supply, water pressure into systems, manostat, emergency systems;
  • electric piezo ignition unit;
  • automatic temperature controllers;
  • warning system and remote control;
  • display with the output of the current performance of the device

Units of this type are more reliable and much more convenient in operation, and in addition, they are economical. Automation can set on and off modes, reducing fuel consumption, create a comfortable microclimate at home, and not worry about safety and performance.

Volatile boiler device
Modern boilers are crammed with electronics. When choosing a device, also install a voltage regulator to protect against surges in the network

The only negative, after a power outage, a volatile gas boiler will not be able to fully work. It is difficult to say exactly which functions will be absent altogether, it depends on the model of the boiler. Some units have a combined control system - mechanical and electronic.

It is exact that forced ventilation, automatic adjustment of the flame supply to the burner, pump, display, electronic control module, in general, all devices operating on an electric drive and constant current supply will not function.

But is everything so scary?

Are power outages dangerous?

Sellers of non-volatile appliances and uninterruptible power supplies tell customers chilling blood stories that look pretty believable. A person who does not understand anything in the boiler device will believe that if there is a loss of current, the gas supply to the burner continues.

What is really going on? When the temperature sensors, the electronic control unit and the pump are turned off, uncontrolled combustion of the fuel in the combustion chamber occurs, which means that the liquid in the heat exchanger overheats.

Accordingly, the tubes do not withstand, deform, burst and water from them extinguishes the burner atmospheric gas boiler. Gas enters the room and creates an explosive situation or simply poisons people and animals. And if the boiler is equipped with a pressurized ventilation system - to the street. It is also unsafe and not environmentally friendly.

Agree, it sounds believable and scary? Already decided to run for a non-volatile boiler? But in vain!

Gas boiler burner
Do not avoid servicing gas appliances and their components. A check will show their operability, especially after power outages

In fact, electrically dependent boilers occupy a leading position in the sales market. They are installed in summer cottages, private houses, with owners spending half a day at work, non-residential premises in which long-term repairs are carried out.

Power outages, as mentioned earlier, the process is quite frequent. And for some reason there is no data on the hourly large-scale tragedies of carbon monoxide poisoning or explosions.

In addition, such a dangerous device would not have passed certification and could not have complied with GOST in any way, which means that its gas workers will not be allowed to operate.

And now the technical details. In fact, there is a reliable system in the devices that ensures the boiler is switched off in case of force majeure, including the interruption of power supply.

Gas shut-off protection devices

Composed of gas boiler automation as a fast-acting locking system, a shut-off valve is often used, popularly called simply a shut-off valve. Unlike other valves, the valve has an automatic response.

Its main purpose is to supply gas to the burner with the desired pressure at a given power and complete cessation of fuel supply in the event of malfunctions. This process is carried out at the expense of control devices with built-in sensors.

Piezo ignition gas valve
Gas piezo blocks are non-volatile, but can be used for both types of boilers

Automation differs in the type of ignition - emit piezo ignition and electric ignition.

Piezo ignition - this is when the launch is done manually, by pressing a button. It monitors the operation of the flame - a thermocouple, which is heated by the igniter and generating a constant current, ensures the open state of the valve.

As soon as for some reason the pilot burner stops supplying an open flame, the electrovalve closes and the gas flow stops. Piezo ignition is a volatile element of automation.

Electric ignition unit connects to a power source. Starting is carried out from an electric spark in an automatic mode. This system is volatile and when the current is turned off, the device valve shuts off the gas supply.

It looks something like this. The differential relay has two contacts. During operation of the heater in normal mode, one unit is closed. When there is any change in the operation of the boiler, for example, the power is turned off, the second unit is triggered, and the first is opened. The relay moves, the membrane bends and the gas supply is cut off.

How long do they turn off the electricity?

If you, having lived a year or two in the village, have not experienced frequent and prolonged power outages, this does not mean that they will not be.

No one is insured and practically nowhere. Even in places close to large cities, there were cases of weekly blackouts due to weather conditions.

Electricians eliminate the effects of freezing rain
In 2016, due to heavy ice rain, entire settlements of the Moscow Region sat without a stable heating for a week.

Usually, the period for which the current supply is interrupted depends on its cause:

  1. Short-term shutdown for a period of half an hour to 2 hours in connection with a scheduled inspection of networks or exceeding limit consumption.
  2. Elimination of emergency situations of a simple nature, connection of new subscribers - from 3 to 6 hours.
  3. Short circuits, KTP malfunction - 12-24 hours.
  4. Serious accidents, coupled with negative weather conditions, the inability to quickly repair the line - from 1 to 3 days.

If the first 3 situations are quite tolerant in terms of time, then under the condition of poor thermal insulation of the house structure or the presence of residents who are contraindicated in coolness, the latter option is extremely undesirable. In addition, even these terms cannot guarantee that even after their expiration the power supply resumes, it is better to be safe.

Many people put an alternative source of heating, for example, a stove, a fireplace, and this, without a doubt, is a reasonable combination when someone is at home constantly and can control the flow, but it is much easier and even cheaper to install a backup power supply system.

How to choose a backup power source?

The most popular option is uninterruptable power sourceabbreviated as UPS.It provides secondary power supply to the device, with a short-term power outage on the line.

Most often it is used to provide power to the computer, so that a person has time to modify, save information and exit the system in the normal mode in case of a power outage from the main source.

Of course ordinary uninterruptible from the computer not suitable for gas boiler. The maximum that he can do is extend the functionality of the device by 2-3 minutes, since the output gives an approximation of a sine wave or meander, and the boiler requires a clean sine. Keep this in mind when buying a device.

Uninterruptible for a gas boiler
The correct choice of UPS for the boiler will allow you to provide fuel even when the power is cut off on the line

Ideally, an uninterruptible power supply of 300-600 W, with the ability to connect a battery up to 600 A * h, is suitable. The capacity of such a battery is enough for 3 days.

But if for some reason you want to save, keep in mind that:

  • 50-100 A * h, extend the operation of the boiler for a period of 3 to 8 hours;
  • 200 A * h - enough for about a day of uninterrupted functionality.

More than 24 hours of shutdown require a more powerful power source. And here it is best to choose an inverter gasoline generator that also has a pure sine wave. Using these devices, the gas boiler will work after disconnecting the load in a stable mode.

What will happen after the restoration of power supply?

One of the most pressing consumer issues is whether a volatile gas boiler will turn on automatically after a power outage.

Depending on the model of the boiler, after the electricity is reconnected, it can be ignited in automatic mode or only after a manual start. Piezo ignition devices will require mechanical activation.

Devices with an atmospheric burner, as well as units with the aforementioned pressurization system, can turn on independently, and even without loss of the set automatic parameters, if they are equipped with electric ignition and a pressure switch.

However, auto-inclusion also does not always work. After de-energizing a large number of subscribers, when electricity is restored, the pressure in the gas pipeline can drop for some time, accordingly, the pressure switch is activated, the equipment does not turn on and you can only start it manually later.

For those for whom this issue is relevant, it is enough to install a delay relay or as it is also called - “time relay". Then your boiler will not start immediately, but after some time, when the pressure in the gas pipeline is likely to equalize.

Delay relay
The time relay allows you to delay the automatic ignition of the electric ignition to the alleged equalization of gas pressure

In some cases, the electronic control module displays an error after power is supplied. This means that there was a small emergency before shutting down. The decoding of the code can be found in the instructions for the heater.

By the way, not all of them can be eliminated on their own, to solve individual problems, you will need to call a specialist from GorGaz or a service department.

Conclusions and useful video on the topic

How to choose a UPS for a gas boiler correctly. Criteria and nuances of the purchase:

So, as we found out, a power outage will not spoil expensive volatile equipment. All systems dependent on electricity will simply shut off and the gas supply will be shut off by a shut-off valve.

And if you also have a UPS installed, you will not even notice a short-term interruption in the supply of current to the line.

Please write comments in the block below, ask questions, post a photo on the topic of the article. Tell us about how your boiler “behaved” after turning off and starting the power supply. Share useful information that is useful to site visitors.

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