Ajax alarm review: an installer's pros and cons

Part of the Costa del Sol security guide

The short answer

Ajax is the brand we specialise in, so bear in mind that this review comes from people who sell and install it. With that said, it is a good alarm if you want equipment you own, with no compulsory monthly fee and no building work. Its real drawbacks are that you pay for everything upfront, that wirelessly it only accepts Ajax devices, that alerts depend on the connection to its cloud and that, without a monitoring centre, you are the one who has to react.

What it does well

No compulsory monthly fee. You buy the equipment and it is yours. The alarm alerts your phone with nothing to pay each month and no minimum contract.
No building work. It is wireless. A flat or an average-sized house is installed in a day.
A photo when it goes off. MotionCam detectors send a photo, so you know whether it is an intruder or the cat before you do anything.
More than one route for an alert. The Hub 2 uses Ethernet and two SIMs. The Hub 2 Plus adds Wi-Fi and 4G SIMs. If the router goes down, the alert goes out over mobile data.
Everything in one app. Alarm, Ajax cameras, other-brand cameras and home automation.
One user per person. Everyone logs in with their own account and the system records who arms and who disarms: up to 50 users on the Hub 2 and 200 on the Hub 2 Plus.

The 7 drawbacks you should know about

1. You pay for everything upfront

An alarm with a monthly fee spreads the cost out over time. With Ajax you pay for the equipment and installation in one go. It usually works out better in the long run, but the first payment is bigger. You can see what it costs in our kits for flats, villas and business premises, with an estimate calculator.

2. It is a closed system

Only Ajax devices connect wirelessly: you cannot add a wireless detector from another brand. If you already have wired detectors, a MultiTransmitter lets you integrate them, but any wireless expansion will be Ajax.

3. It depends on the Ajax cloud

Setup, the app and notifications all go through Ajax's servers. If the hub loses every connection, you cannot see or control anything remotely. It stores the events and sends them once it is back online. That is why a hub with a SIM is the sensible choice for a second home.

4. The hub battery has a limit

The hub lasts up to 16 hours without mains power on the Hub 2 and up to 15 on the Hub 2 Plus. A longer outage in an empty house will drain it. Battery saving mode extends this, but according to the Ajax manual the system no longer meets Grade 2 with that mode switched on.

5. Nobody reacts for you

Without a monitoring centre, the alert goes to you and to anyone you have added. If you are on a plane, it is worth having someone else on the app. A monitoring centre is provided by a registered private security company, not by Dartel. We explain it in monitored alarm or phone alerts?

6. Ajax cloud video costs extra

Ajax Cloud Storage is an optional subscription and each distributor sets its own price. The alarm does not need it, and Ajax cameras can record to a microSD card or a recorder. But if someone tells you everything Ajax comes with no monthly fee, this is the part they left out.

7. The radio signal does not get through everything

Thick walls and metal cabinets cut the signal. A large villa may need a ReX 2 range extender, which is added to the quote. That is why we test the signal detector by detector before we leave.

Who it suits and who it doesn't

Your situation	Our view
A flat or house, and you don't want a monthly fee	A good fit. This is what it does best.
A second home	A good fit, with a SIM in the hub and a contact person nearby.
A villa with thick walls	A good fit, once the signal is tested and with a range extender if needed.
You want someone to verify the alarm and call the police	Ajax works, but you contract that monitoring centre with a registered company.
You want to spend as little as possible upfront	First read Ajax or Dahua: Dahua is usually cheaper to expand.
You have a wired alarm that works	Replacing all of it may not be worthwhile.

Frequently asked questions

Is an Ajax alarm worth it?

Yes, if you want equipment you own, with no compulsory monthly fee and no building work, and you accept paying for everything upfront. It makes less sense if you want the lowest initial cost or already have a wired alarm that works.

Does an Ajax alarm have a monthly fee?

Not a compulsory one: the alarm alerts your phone with no monthly fee. You only pay extra if you contract a monitoring centre with a registered company or use Ajax's cloud video.

Can I use detectors from another brand with an Ajax alarm?

Not wirelessly: it only accepts Ajax devices. Wired detectors from other brands can be integrated with a MultiTransmitter.

Does an Ajax alarm work without internet?

If the hub has a SIM, it keeps sending alerts over mobile data when the router goes down. If it loses every connection, no alerts arrive and you cannot control it remotely; it stores the events and sends them when the connection returns.

What warranty does Ajax offer?

The manufacturer gives 2 years from the date of purchase. The batteries included are not covered by that warranty.

Are the opinions on this page from customers?

No. This is the opinion of Dartel Solutions, which sells and installs Ajax. The technical data comes from the manufacturer's data sheets and manuals.

Is Ajax right for your home?

Send us the floor plan or a few photos and we will tell you whether Ajax suits you, what you need and what it costs, with an itemised quote. Site visit and quote with no obligation. We speak English, Spanish, Russian and Ukrainian.

Ask for a quote on WhatsApp See Ajax alarm kits

Sources: Hub 2 Plus manual (ajax.systems/support/manuals/hub-2-plus), Ajax Systems warranty (ajax.systems/warranty), Ajax Cloud Storage (ajax.systems/blog/ajax-cloud-storage-plans) and dartelsolutions.com product pages (Hub 2, Hub 2 Plus, MultiTransmitter, ReX 2, BulletCam). Checked in October 2026.

Ajax alarm review: the pros and cons before you buy