Left Luggage for LARGE items at Heathrow?

Not sure of the size restrictions, but found this: http://www.left-baggage.co.uk/locations.php

For what it is worth, in Terminal 4, as you exit the secure area, all the way to the right, at the end of the terminal is a left luggage. It is one where you go to a manned counter and they have a storage area, not lockers...so an oversize item should not be an issue...not positive...just an observation as I walked through.

LeeB and Paul-thanks much, I think you guys are referring to the same place, and that should work fine. I'll paste in the response I received to my inquiry on large items here for the benefit of others; thanks again!
This service is available at the major London Airports, major train stations, as well as some locations in the north of Britain.

London Heathrow Airport Left Luggage Service: We have storage facilities in all four terminals at Heathrow Airport.
0-2 Hours - £5.00 2-24hrs - £10.00 24hrs+ - £5.00 per item/per 24hrs or part thereof.
Our storage facilities are monitored by 24 hour CCTV surveillance. Items can be stored for up to 90 days at the rate above.
At present there are no restrictions on the size of each item, but there is a weight limit of 32kg per item.
On arrival, please follow signs for Left Baggage.
Opening times and locations below:
All our Airport facilities are open seven days a week
Terminal 1: 06:00 - 23:00 Located in International Arrivals
Terminal 3: 05:00 - 23:00 Located in Arrivals opposite Car Hire Desks

Terminal 4: 05:30 - 23:00 Located in Arrivals next to Underground access

Terminal 5: 05:30 - 23:00 Ground floor next to Domestic Arrivals

We do not hold pre reservations for storage, bookings are done only upon arrival to Heathrow and payment is made upon collection of your goods.