I have a problem with my car not getting heat for about the first 15-20mins when the temp is at or below 15F so I guess it's the solenoids

No your problem is that the engine is still cold, or you have a thermostat that is stuck in the open position.

My thermostat is less than a year old and gauge reads fine. And when I say I'm not getting heat for the first 15mins I mean I'm driving for 15mins and the temp gauge could be half way and the car is still blowing out pure cold air but it only happens when the temp is around 15f or less

Get actual coolant temp numbers. The gauge isn't the most precise method of determining coolant temp. If your engine coolant temp is getting up to the 90*C range and you still don't have heat, or have mediocre heat at best it's likely your valves are shot as well.

With this cold weather this year, were probably going to be seeing a lot more of these sorts of heating problems become prevalent.

Also, resources like Inpa (and I'm sure DIS) are invaluable when trying to figure out heating issues since you can see the coolant temps across various areas of the system.

This all assumes that you have bled the system correctly and don't have an air pocket in your core.

You're in NorCal... Put on a light jacket, open the sunroof and get your cruise on. :)

If your cluster is UNLOCKED...what coolant temp (KTMP) range do you see when you run TEST 7. TEST 7 is a better indicator than the "buffered" gauge which doesn't indicate the constant flux of the coolant's temperature

The 1st screen of TEST 7 allows you to monitor coolant temp (in Celsius)...you can do this while driving around town (I'm assuming that you have the high cluster since you still haven't created a signature so that we know the correct info to post)...if you have the low cluster, you can still get this info but the display & screens are slightly different due to it not having the 20 digit alpha/numeric display:


If your coolant temp is within normal operating range...then this would suggest that the issue may be the water valve/aux pump (aka heater valve) or the heating radiator.

Well it only happens when the temp is around 15f or less so if it happens again I'll check that