Every time the thermostat tries to switch the heater on, the pilot light goes out. Cozy natural gas mod # CDV 335A

There are two types of igniters, spark-type or glow heater. The glow heaters wear out and crack or break and the spark-type spark gap gets fouled or dirty. Both could have electronics problems that drive the glow heater or spark systems. The Filtrete thermostat is not the issue. While rapping the unit makes the glow igniter come back together to glow again.

need to change the gas valve and add a pilot generator and stat wire and a wall stat. If your unit is natural gas part numbers are gas valve 84085// pilot gen. 70098.

if the pilot will not light and you have natural gas remove pilot tubing and pilot orifice and clean out.

its not the valve you have a problem with the heat exchanger a baffle issue have to change.

The thermocouple needs to get red hot. If the pilot flame is too low or too high or if it is not pointed on the thermocouple well, it won't stay hot enough. If the pilot flame is too low, a draft caused by opening a door could blow it out. If correcting this doesn't fix it, it could be a bad thermocouple or control. The factory assembly on these heaters is not the best.

go to www.cozyheaters.com for full install instructions.

get someone to check the gas pressure that is poss problem gas company if nat and the lp supplier can do it

no more than 20 feet of statr wire allowed and make sure the stat you have is for a millivolt system.

That piece that fell out is probably the pilot orifice. It goes on the end of the pilot gas line when you screw it into the pilot assembly. Don't try to light the heater without the orifice. If your thermocouple is good and the pilot flame is set properly, the control valve could be bad. Be sure to hold the knob down for 60 seconds before releasing it.

The VC701 has a safety switch located on the back of he heater that may be tripping after the call for heat is satisfied. Check that there is a good draft by testing with a match. Make sure the flame is drawn toward the vent system when the unit is off and cooling down. Check it at the draft diverter located below where the vent pipe is attached. It is a box with an open bottom. If the draft is not pulling air toward the vent system, the heat from the cooling heater will trigger the safety switch and shut off the pilot. You may have to raise the vent pipe to establish a draft.