Cheap Mode 2.4.11: the cheapest Nord Pool hours, now on one clear screen

We rebuilt Cheap Mode in the GPO Home app after feedback that the old setup was too complex. Both strategies, both power levels and a plain-language summary now live on one screen — so you can see exactly what your plug will do before you press Activate.

A water boiler does not care when it heats. Your electricity bill does. If you use the GPO Smart Plug on a spot-price tariff, Cheap Mode has always been the feature that moves your hot water — and your heaters, and your EV — into the cheapest hours of electricity each day.

What it did not always do was explain itself. The old Cheap Mode screen kept the cheap-period behaviour and the rest-of-the-day behaviour in different places: you picked an action for the cheap window, then had to remember how the plug would behave outside it, and a separate device step decided the details. Plenty of people ended up with a plug that quietly ignored the schedule.

Version 2.4.11 is a direct answer to that. The views were rebuilt around one question: what should the appliance actually do, on both sides of the schedule? Both answers now sit on one screen, next to the price chart, and a summary card reads the whole setup back to you in sentences.

Short walkthrough: the plug switched on, the power levels moved, and the summary reading the setup back before activation.

This guide covers both strategies, the rule behind the classic "Cheap Mode does nothing" setup, what the percentages mean, and how to set up a water boiler or a heater.

What Cheap Mode does

Cheap Mode reads the Nord Pool day-ahead electricity prices for your country and controls your appliance automatically.

• Prices are handled in 15-minute intervals — 96 price points per day, for today and, once published, tomorrow.
• Hours are selected per calendar day in your local time, and the schedule is recalculated when new price data arrives.
• The plug receives its schedule over the internet, so it needs to stay online.
• Cheap Mode works in Estonia, Latvia, Lithuania and Finland, using the Nord Pool prices for the plug's country.
• The GPO Home app is free for iOS and Android, with no subscription.

Exchange prices in, appliance control out — that is what makes the GPO Smart Plug a Nord Pool smart plug rather than a timer.

The rest of Cheap Mode works as before. What changed is how much of it you can see at once.

What's new in app version 2.4.11

Both sides of the schedule are visible. For Cheapest Hours, the screen shows Power during cheap hours and Power outside cheap hours on one screen, one above the other. For Price Ceiling, it shows Power below price ceiling and Power above price ceiling. There is no longer a separate "Apply for devices" action to guess at: the two power levels on the screen are the behaviour.

The summary speaks plain English. The Cheap Mode Summary card turns the sliders into sentences — "During 5 cheapest hours: Device runs at 100% power", "During remaining 19 hours: Device stays off" — and reads the current settings back before you activate. If a sentence is not what you expect, you have found a mistake before it reaches the appliance.

The chart shows the selection, not just the prices. In Cheapest Hours mode the intervals the app has picked are highlighted brighter. In Price Ceiling mode your ceiling is drawn as an orange dashed line, and the intervals below it — where the appliance runs at the below-ceiling power — are highlighted. Change the number of hours or the ceiling, and the highlight moves with it.

The names are clearer. Cheapest Hours was previously called "Working hours", and Price Ceiling was "Price threshold". The "Working hours" field name survives inside the Cheapest Hours configuration.

The engine behind it is the same: 15-minute Nord Pool prices, daily recalculation, free app.

Cheapest Hours or Price Ceiling? How to choose

Cheapest Hours runs the appliance for a set number of hours each day, always in the day's cheapest intervals. You do not pick clock times; the app fills your hours from the bottom of the price curve upwards. This is the strategy for anything that stores its result — a water boiler, underfloor heating with thermal mass, an EV charger, a towel dryer.

Price Ceiling sets a maximum price per kWh. Below your ceiling the appliance runs normally; when the price reaches your ceiling or goes above it, the appliance falls back to the level you choose — off or reduced. This is the strategy for loads that should mostly keep running, and for heaters that should hold a room temperature with a cheaper fallback for the peaks.

The rule that quietly breaks setups: keep the plug switched on

This is the one point worth reading twice, because it explains the classic "Cheap Mode does nothing" setup.

If the plug itself is switched off, it stays off. The OFF state overrides Cheap Mode, and the schedule cannot turn a switched-off plug back on. The intuitive setup — "leave the plug off and let Cheap Mode switch it on when electricity is cheap" — silently does nothing.

There are two different "offs" in the app, and they do different things:

• The plug's own switch off, on the device screen, stops everything. The plug ignores its schedule until you switch it back on.
• A power level of OFF inside Cheap Mode is part of the schedule: it means the appliance receives no power during that period, and the schedule switches it back on when the next cheap window starts. The summary states it as a sentence — for example, "During remaining 19 hours: Device stays off" — and that is the setting doing its job.

So the rule in one line: the plug switched on, and the power levels inside Cheap Mode doing the switching.

If you followed our older guide, you may remember setting the plug's Manual mode power ratio to 0% and choosing an action for the cheap window as two separate steps. In 2.4.11 both of those become the two power sliders on the Cheap Mode screen. The underlying rule is the same one as before: the plug itself stays on.

What the percentages mean

Every percentage in Cheap Mode is the plug's power ratio: the share of time the socket keeps power on inside a repeating 5-minute cycle.

For a water boiler, use 100% inside the cheap window: you want the tank to reach temperature before the window closes. Lower ratios are for loads where you want to limit average power instead of switching cleanly on and off.

How to set up Cheapest Hours for a water boiler

1. Update GPO Home to 2.4.11 and open your plug. Make sure the plug itself is switched on and shows as online.
2. Open Cheap Mode and choose Cheapest Hours.
3. Set Working hours to the number of hours your boiler needs — for example 3. The app will use the 3 cheapest hours of each calendar day.
4. Set Power during cheap hours to 100%. This is the heating window; the boiler should run at full power while it lasts.
5. Set Power outside cheap hours to OFF. The appliance gets no power between windows. If your load needs a trickle instead, use 25% — the summary will show the difference.
6. Read the Cheap Mode Summary. It should say that the device runs at 100% power during the chosen hours and stays off (or falls back to the level you set) outside them.
7. Press Activate and keep the plug online. The schedule is delivered over the internet.

Two things to expect on the first day. Hours are selected per calendar day, so activating in the afternoon gives a shorter first day — part of that day's cheapest hours has already passed. And the cheap hours are rarely consecutive: a morning block plus an evening block is the feature working, not a bug.

How to set up Price Ceiling for a heater or another load

1. Keep the plug switched on and open Cheap Mode.
2. Choose Price Ceiling and set your maximum acceptable price per kWh. Use a level you would be comfortable paying for most of the day, then adjust after a few days of statistics.
3. Set Power below price ceiling to 100%. This is the normal running state: while the spot price is below your ceiling, the appliance runs as usual.
4. Set Power above price ceiling to OFF to pause the load during expensive peaks. Use 25% instead if the appliance should not stop completely.
5. Check the chart. The orange dashed line is your ceiling; the highlighted bars below it are the intervals that run at the below-ceiling power.
6. Read the summary and press Activate.

One caution: on an expensive day, most hours can sit above your ceiling, and the appliance may stay in its fallback state for a long stretch. That is the strategy working as set. If it is not what you want, raise the ceiling temporarily or switch to Cheapest Hours.

The summary card is your last check before Activate

The Cheap Mode Summary is the part of the redesign we think matters most. Instead of translating sliders in your head, you read the result: during the cheap hours the device runs at this power; outside them it does that.

It is the simplest check for a mistake — a fallback level left at 100%, a ceiling almost nothing falls below, or a heater that would keep running exactly as before. Because it reflects the current settings, you can try a different value and read the consequence before activating.

When you change a setting after activation, deactivate the schedule and activate it again, so the new values are applied immediately rather than at the next daily refresh.

What to expect after activation

• Different hours every day. The schedule follows the exchange, so tomorrow's windows will not match today's.
• The chart shows the intervals the app has selected before you commit; the summary states the resulting behaviour.
• Statistics show the result. If the outside or above-ceiling power is OFF, consumption should appear only inside the selected windows — the simplest way to confirm the setup does what the summary says.
• The plug needs the internet. An offline plug picks up its latest schedule when it reconnects.

How many hours should you choose?

Enough to heat the tank, and no more. Every extra hour is bought at a progressively worse price, because the app fills your requested duration starting from the cheapest intervals.

As a rule of thumb, a typical 80 L / 2 kW boiler heats a full tank from cold in roughly two to three hours — check the label on your own boiler, or look at the plug's Statistics screen to see how many hours a day it currently draws power. Start there, live with it for a few days, and add an hour only if you run out of hot water.

If you heat with GPO heaters

If a GPO heater is linked in GPO Home, the same Cheap Mode screen also carries its settings. You can set the target room temperature and the heater's maximum surface temperature separately for the cheap state and the fallback state, and decide whether the heater keeps heating outside the cheap hours. The summary reads those targets back too — for example, "During 3 cheapest hours: Device heats to 20°C, heater surface capped at 85°C."

For heater owners, Price Ceiling is usually the more natural strategy: keep the room comfortable while electricity is below your limit, and set the fallback state for the peaks — a lower target temperature, or off if the appliance can stop for a while.

If Cheap Mode doesn't seem to work

• Check the plug's switch first. A plug switched off ignores Cheap Mode completely.
• Check the summary, not the sliders. It states what will happen in each state. If the summary is right, the behaviour is right.
• Check the fallback power level. A setup where Power outside cheap hours is also 100% gives the appliance full power all day, which looks like Cheap Mode doing nothing.
• Check the ceiling in Price Ceiling mode. If every hour is above it, the appliance stays in the fallback state all day.
• Check the connection. The plug must be online to receive its schedule.

Frequently asked questions

Why does the boiler run in several blocks instead of one long block? Because the cheapest hours of a day are rarely consecutive. The app follows the price curve, so it runs in whatever blocks are cheapest that day.

Why did it run fewer hours today? If Cheap Mode was activated in the middle of the day, part of that day's cheapest hours had already passed. It works in full from the next day.

What is the difference between Cheapest Hours and Price Ceiling? Cheapest Hours runs the appliance for a set number of the day's cheapest hours. Price Ceiling runs it normally below your price limit and falls back above it. One finds the cheapest time; the other caps the price you are willing to pay.

Does Cheap Mode work without the internet? No. The plug needs a connection to receive its daily schedule. If it goes offline, it picks up the latest schedule when it reconnects.

Which countries are supported? Estonia, Latvia, Lithuania and Finland, using the Nord Pool prices for the plug's country.

Is the app free? Yes. GPO Home is free for iOS and Android, and Cheap Mode has no subscription.

Can I use it for an EV charger, floor heating or a towel dryer? Yes — anything that stores its result works well with Cheapest Hours: water heating, underfloor heating with thermal mass, EV charging, a towel dryer. The principle is the same: plug switched on, power outside the cheap hours at OFF, full power inside them.

Can I set a different room temperature for cheap and expensive hours? Yes, if a GPO heater is linked in GPO Home: Cheap Mode shows target room temperature and maximum heater surface temperature for each price state, and reads them back in the summary.