Thermostat/ temperature

Got a 300TDI defender, it’s always run a bit cool to the point the heater isn’t hot, gauge shows about 1/4.

Decided to change thermostat see if any improvement, put in a 88 degree and now the gauge is almost at top of black, but not ‘boiling’

Original was a Waxstat.
Put them both in a pan and the waxstat opens at a lot lower temperature than the new one.

Is the new gauge temp too high and do waxstats open at lower temperature than the 88 degree ones.Not altered anything else.

Steve

Isn't that about right if the engine is hot?
You need to test the coolant temp with one of them hand held temperature gun thingies. If all OK then all you need to do is keep that temp position as normal running temp.
My son's 200tdi did exactly the same thing after fitting a new thermostat except it sits even higher. It's doesn't over heat, proven with a secondary gauge .

One of these