Welcome to the intruder alarm page

Areas Covered in Hertfordshire include

Stevenage Hitchin Letchworth Baldock Knebworth Welwyn Walkern Hatfield St.Albans Hemel Hempstead Harpenden Watford and surrounding areas.


External siren units



Wireless  Pet friendly PIR detectors


LCD Keypad with
tag reader built in.


Remote control 
setting and panic  fobs


Fixed price alarms supplied Gardtec 595 with 8 wired zones available and 8 wireless zones expandable to 16 with an additional radio receiver and installed with 4 wireless Pirs, 1 wireless door contact, 1 Remote control, Siren strobe unit ,decoy siren strobe unit for rear, G tag lcd keypad  650 inc Vat

Additional Pir 50,  door contacts 45, Remote control 45, extra 8 zone radio receiver 55, Dialler system linked to your telephone line to let you know if the alarm has been triggered 55



We have been installing and maintaining alarms for 15 years now, there are many good makes of equipment but we tend to stick to the ones we are used to using, new models come out within the range we use but the programming is often identical. it depends on what you want to do with an alarm as to what one we recommend. We like to view a property to see how an installation will be approached and to listen to the customers requirements. Systems that need to be linked to a monitoring station will need to be of a certain standard, and often dearer than a bells only system.


Types Of Alarms

There is basically wired alarms and wireless alarms, some are out now which mix the two technologies, not many wireless alarms are completely wireless, for harsh environments such as garages with leaking doors, conservatories etcetera there is more choice in the wired type of Pir sensors.

The wireless market has expanded rapidly recently with availability of wireless pet sensors ,shock sensors and remote controls


Monitored Alarms

Monitored alarms can use A digicom which sends a signal down the phone line this is the cheapest type of monitoring an alarm . approx 160 per annum charges, up from that we have the redcare gsm which is a digicom with a cut line monitoring system and a mobile phone built in to dial up if the normal line is down, approx 400 per anum plus Vat this will cost

It has to be remembered that the monitoring company will not inform the police unless it is a confirmed alarm this is by the activation of two sensors not including the front door, this is mainly to stop police attending false alarms.

The cheapest method with no ongoing charges is the home dialler type which can ring your mobile and let you know the alarm is going off or that the panic buttons have be pressed, or that a smoke detector has activated.



An alarm should be checked annually and the battery inside the control panel should be changed at least every 4 years, we can service alarms for 55, batteries and replacement parts are extra.



Email sales@grange-security.co.uk Tel 01438 358344