Oil filled radiator not hot enough after thermostat replacement

limited information didnt specify year or size --is radiator clean --fluid level correct any accessories in way of rad if larger size is stat working correctly --old oil? oil level correct oil cooler dirty or clogged

start a cold engine and let it idle . After about 10 minutes you will feel that the top radiator starts to get hot. This indicates that the thermostat is opening and allowing hot coolant through to the radiator. This means that the thermostat was replaced . Point of interest here . Water pumps no not cause over heating. They will have seal and bearing failure but other than that they never cause overheating unless they are 50 years old and rusted away at the impeller. A new pump will be shiny clean.

Holts Wondarweld
Flush engine.
EXTERNAL CRACKS
1 Run engine until hot,drain off enough coolant to remove thermostat.
2 Remove thermostat.
3 Mix contents of can thoughoughly! and pour contents into thermostat opening.
4 Replace thermostat cover.& fill radiator with hot water,replace radiator cap.
5 Run engine at a fast idle for 15 mins,dont allow to boil.Top up if necessary.
6 Leave Wondarweld in system for 2-3 days then drain off,flush system replace thermostat and refill.
HAIRLINE CRACKS
1 MIX thoroughly and pour into cold engine (radiator if it has a cap)
2 Run engine until hot.
3 Allow engine to cool then run again until hot.
4 Follow procedure 6 above.
INTERNAL CRACKS
1 Follow external crack instructions except after pouring Wondarweld into engine remove spark plug from
affected cylinder and run engine for 20 mins. If more than one cylinder affected run for 5 minute intervals.
2 Allow engine to cool then drain cooling system and refill with clean water.
3 Drain sump & flush,refill with fresh oil.
Note:- 1/2 pint of Wondarweld for every 6 pints of water,DO NOT add antifreeze for at least 3 days after process.

have you had the thermostat replaced

Try with the small stuff first. Replace the thermostat. Before you do that, you should flush and refill your system with just water after the flush process. The bottle of solution that you put into your radiator to flush it and clean it has instructions, follow those. Then let the car cool down and drain the system and refill it with fresh water only. Run this water for a bit and then do it once more. Once cooled back down , replace thermostat and replace the 50/50 mix of antifreeze and water.
Check engine oil level as well, low oil will overheat engines quickly.
NEVER REMOVE THE RADIATOR CAP ON A HOT ENGINE. !
NEVER REMOVE THE RADIATOR CAP ON A HOT ENGINE. !!
NEVER REMOVE THE RADIATOR CAP ON A HOT ENGINE. !!!

REPLACE RADIATOR PRESSURE CAP AND CHECK THE COOLING FAN CLUTCH.WHEN YOUR ENGINE HOT WHEN YOU TRY TURNING CLUTCH FAN WITH YOUR HAND WHEN ENGINE IS HOT.THERE SHOULD BE RESISTANCE IN THE FAN.IF CLUTCH FAN SPINS FREELY WHILE ENGINE HOT.YOU NEED TO REMOVE COOLING FAN TO REPLACE CLUTCH.

yeah they do that, time for a good cleaning, if that fails, I'd replace with a ceramic heater... they are cheaper safer and cost less to operate.

No, as it doesn't get hot enough to start a fire. The only thing that would be dangerous to your carpet would be if it leaked oil and stained it.

This could be many things - like the thermostat, the wiring, one of the heating elements, etc. Unless this unit is less than 3 years old and depending on the use, it might be less expensive to replace it.

Your thermostat could be bad, getting stuck. I had that happen. While driving down the road I noticed the guage went way over to the hot side then went back. I changed it and all is well. It will run hot if there is something blocking the air flow through your radiator. Good clean oil up to the fill line will help your engine run cooler. If you havent changed your oil and filter lately, the oil filter may be clogged (full) and the oil is bypassing it. This will leave gunk and metal parts in the oil that make the oil hotter than it should be. Make sure your coolant level is topped off and you have antifreeze in it. The proper mixture of antifreeze helps keep an engine cool. If there is too much grease and oil buildup on the outside of your engine it will run hotter because the air flow cannot reach the metal and cool it off. Is your radiator clogged. Some people, if they have a leak in the radiator will use stuff to seal it from the inside. These additives can clog the radiator. 
HAVE YOU RECENTLY WORK ON ANY REPLACEMENT FOR YOUR THERMOSTAT?
Are you sure you have the right thermostat ?