Map template not finding location

I'm having a problem with a new site and Google maps using the map.html template. The Find address button doesn't appear to find my location (using a UK postcode). I can zoom and pan the map to find an approximate location but there's no map pin.

I have created and entered a Google Maps API key and assigned the appropriate referrers on Google Dev site.

I have saved my region. Is there anything else I need to do to create a map with location pin?

My Short DIagnostics:

Perch: 2.8.31, PHP: 5.5.21, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: bf9ad53b11c9a57efdb1057292d73b928b8c5c77 $, with PDO
Server OS: Linux, cgi-fcgi
Installed apps: content (2.8.31), assets (2.8.31), categories (2.8.31), perch_forms (1.8.3)
App runtimes: <?php $apps_list = array( 'content', 'categories', 'perch_forms', );
PERCH_LOGINPATH: /perch
PERCH_PATH: /home/horshamcoworking/public_html/perch
PERCH_CORE: /home/horshamcoworking/public_html/perch/core
PERCH_RESFILEPATH: /home/horshamcoworking/public_html/perch/resources
Image manipulation: GD
PHP limits: Max upload 8M, Max POST 8M, Memory: 128M, Total max file upload: 8M
F1: 2edba60ed1f613d6dd804feb202456a2
Resource folder writeable: Yes
SCRIPT_NAME: /perch/core/settings/diagnostics/index.php
REQUEST_URI: /perch/core/settings/diagnostics/
DOCUMENT_ROOT: /home/horshamcoworking/public_html
HTTP_HOST: horshamcoworking.co.uk

and my template (I have RWD defined in config.php)

<div>
    <h2><perch:content id="location" type="text" label="Location name" required="true" title="true" suppress="true" /></h2>
    <perch:content id="map" type="map" label="Address" zoom="15" />
</div>