I have heating upstaires on 3 rads but nothing downstaires. Tried to find the Pump but no luck, will it be next to the boiler? I have a old baxi back boiler, could it be behind the plaster board next to the boiler or contected to the theromstat in the hall. Which would mean its under the floorboards. Already had the floorboards up in the kitchen with no luck. Any help appreciated. Tony