The heater control valve can not be causing your problem.
The top rad hose should become hot when the engine is at its normal running temperature. what you may have here is a circulation problem.
Blocked/clogged radiator, internally collapsed lower/upper radiator hose, defective water pump, defective thermostat (not opening), major air lock in the system.
Other possible causes: defective water reservoir cap
Combustion gas entering the cooling system (Faulty head gasket, cracked head.
Jackd