First: This requires Tier 3 Paladin (Redemption) set.
1. Lay on Hands is a 20 minute cooldown.
2. With the new Lay on Hands glyph on the PTR it's 5 minutes off the cooldown.
3. The Improved LoH talent is another 4 minutes off the cooldown.
4. The Four-Piece Tier 3 bonus is another 12 minutes off the cooldown.
In short: You have a 15k+ spammable heal without a cooldown (other than GCD) or mana cost to abuse on the PTR and help trivialize learning encounters in Ulduar. There's a slim chance this will go live, which is why I stated that it's a PTR exploit. Abuse it and enjoy it, if you have the gear in your bank still.