If it possible to setup the 2820 to use both WAN's to increase bandwidth?

Model Name : Vigor2820
Firmware Version : 3.3.3_232201
WAN1 - Connected to 18Mb ADSL
WAN2 - Connected to 10Mb WiFi Internet

All the setting seems to refer to failover / balancing of traffic by type.
All I can acheive is sending traffic down WAN1 OR WAN2, but not balanced across both.

I am trying to gain more bandwidth for downloading from GigaNews.
from one PC.

The 2910 model refers to 'loadbalancing...just for increased total bandwidth'

The 2820 will automatically load balance, (as long as you don't set restrictions), but balancing is done "per session", so if you want to increase the bandwidth allocated to a single download, you will have to use some sort of download manager. I use ReGet Deluxe, and I do get some combining of WANs, but it doesn't seem to kick in for a few minutes, and even then it's a little hit and miss, I'm afraid

How should the 2820 be setup to support load balancing?
I am generating multiple downloads, but all traffics goes via
WAN2. Cannot hget any traffic to go via WAN1

My current config is:

WAN >> General Setup
Load Balance Mode (WAN1 + 2) = Auto weight

WAN >> Load-Balance Policy
1 Enable Protocol=Any WAN2
2 Enable Protocol=Any WAN1

The load balancing policy is really only used to ensure that certain IPs or ports use specific WANs. For instance, some online bank security systems may not like to see access from apparently more than one public IP, so it's a good idea to set a load-balancing rule to limit traffic on port 443 to one WAN only (this is the port used for accessing https:// web pages).

You have set a rule to say that all traffic is to use WAN2, and then followed it by a rule that says that all traffic is to use WAN1. I supect that it is acting on the first rule, and ignoring the conflicting second rule. Try un-ticking both, and see what happens - it may take several minutes before the router starts to use both WANs.