mt temperature gauge fluctuates alot recently. it waill be slightly below half way where it should be, then sometimes it will creep up to a little below the "H". stay there for awhile then go back down to normal. i have antifreeze in it and the heat blows very hot. any ideas? it makes me nervous!

 

You may have air bubbles trapped in the lines. Just CAREFULLY bleed it and the problem should go away.