I have to kind of disagree with the group thought here.
In 4e, it shouldn't matter how many surges the PCs have, because there are only limited ways to ACCESS those surges during battle. You have one Second Wind (which costs a standard action for non-dwarves), potions (which cost significant money), and leader powers (most of which are encounter based and in short supply).
There's not much of a 'health nova' issue because having 12 surges doesn't help if you can only use 3 per battle (and that's if the cleric ignores everyone else's needs). The system is designed to be largely day-independent. Surge count is a way to curtail the "we can adventure forever!" problem that's the inverse of the 3.5 "five minute workday" issue, and I believe it was Dave Noonan who commented that if your party could be trusted not to abuse it, you could pretty much do away with the daily surge count without hurting anything.
The real issue with one combat per day is the ability for the PCs to burn all their daily powers on that one fight, which naturally means they can deal 25 or 30% more damage than in a fight where they're being more conservative. Maybe you're seeing low damage totals not due to surging but because the monsters fall quickly to daily power usage.
The surge tally shouldn't be what makes them 'fear no monster'. Have you checked that you're building your encounters correctly? An on-level fight is X monsters of level Y (where your party is X characters of level Y), or a group of monsters with the same XP total, or a single solo monster of the appropriate level (though you have to be a little careful with that if you don't have exactly 5 PCs). If you're throwing easy fights, it's no wonder the PCs win handily.
However, if healing really is the issue, make sure you are enforcing the limits on use of healing surges. If the cleric is using more than 2 Healing Words per fight, or if you have people Surging without giving up their action to do so (except dwarves), or if you have people using Second Wind more than once per fight, that could cause the problem.
If none of those are a problem, I guess I'd just ask, what is it that makes you think things aren't right? Is it just that they go to bed with 10 surges still in the box? So what? If the cleric is out of Words and I've used my second wind and I have no potions and I'm down to 5 HP, I'm just as close to dying as the guy with 5 HP and no healing surges left. The fact that I have 10 sitting over there doesn't help me, because I have to get out of the fight alive before I can rest and use those to recover my HPs.