TAKE CARE WHEN BUYING THE UNIVA GAS STOVE FROM RUSSELS

Russels on line shop service is very poor and the quality controll of the univa gas stove is to be questioned. I purchased a Gas stove on the 10th April. When I had it installed we found the oven does not work. It fires up but the flame go out as soon as the gas valve is released from the start position even after holding the valve button for longer than a minute instead off 5 seconds. It seems like the flame detector does not work. How is this possible as this is a safety future it should have been tested properly before the stove left the factory. I lodged a complaint fo9r a repair or replacement stove 10 days ago and up to now no answer from Russels or Univa.They are quick to sell but slow after service