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BoilerBuddy

For your solar water heater at home

Always know how your solar water heater is doing.

The BoilerBuddy Alpo sits next to your solar water heater and keeps an eye on it, day and night. You see what the sun heats up today and what you save. If something isn't working, you hear about it right away.

Create an account Try the demo

The Alpo only watches. Nothing about your system changes.

Example installation

Today, 14:00

Example data

Collector

60.7°C

Tank top

46.5°C

Tank bottom

43.9°C

Solar today

4.3kWh

Everything is working as it should
An example of the BoilerBuddy portal, with example data.

How it works

Connect it, pair it, see what's happening

  1. 01

    Connect the Alpo

    You connect the Alpo to your solar water heater's controller, and to your router with a network cable. It works with OEG's solar controllers: the KSW-E, KSW and KS2W.

  2. 02

    Pair it with your account

    Your Alpo's status page shows a pairing code. Enter it in the portal, and from then on you see your readings.

  3. 03

    See what's happening

    See what the sun heats up and what you save. If the pump stops, the Alpo goes offline or the collector on your roof gets too hot, you get an email.

More about how it works

What you get

Everything about your solar water heater, in one place

A solar water heater works quietly. When something goes wrong, you often don't notice: your water still gets hot, because the boiler takes over. BoilerBuddy shows you what's really going on.

From today to years back

See how warm the collector on your roof and your tank are, and when the pump runs. Zoom out to a week or a year and see how things change with the seasons.

CollectorTank topTank bottomPumpPartly cloudy day

An email when something's wrong

BoilerBuddy knows how your solar water heater should behave. When something goes wrong, you get an email saying what's up and where to look. And once it's fixed, you hear that too.

  • The pump isn't running while the collector is hot
  • The Alpo stops checking in
  • The collector gets too hot
  • A sensor sends nothing or gets stuck

What the sun gives you

See how much heat the sun delivers per day, month and year, and how much gas, money and CO₂ that saves you. We use your own tank, boiler and gas price. It's an estimate, and we say so.

Solar yield

655kWh

Gas saved

83m³

Saved

€116

CO₂ avoided

147kg

Real figures from one solar water heater in 2025: a 200 litre tank, 90 percent boiler efficiency and gas at € 1.40 per m³.

Share with your partner or installer

Invite someone to keep an eye on things with you. A viewer sees the charts and alerts. An installer can also update your system's details. You stay the owner.

Open API, also for your own hardware

The Alpo uses an open API, and you can use it too. Connect your own hardware and see its readings in the same portal.

Go to the developer page

Rather have an installer do it?

In the installer directory you'll find a company in your region that connects the Alpo for you and keeps an eye on things with you.

Find an installer

For installers

See your customers' systems without driving out

Your customers share their BoilerBuddy with you. You see their charts, get the same alerts, and already know what's going on when they call.

More for installers

Frequently asked questions

Will it work for me, who sees my data, and what if the internet goes down?

Short answers to what people ask us most.

Read the answers

Curious what your solar water heater is up to?

Create a free account and see how it works in the demo. The BoilerBuddy Alpo will be for sale soon; with your own hardware you can send readings right now.

Create an account Try the demo