Oil tank caps

[Bertieeee]

Bit of a daft question, but I'll ask it anyway. I've recently moved into a house with oil heating, and I'd like to check the oil level. There is a watchman sonic thing, however I want to be able to do it manually for my own piece of mind. I've gone to the tank and was expecting to be able to put a long piece of wood in there, however there's two caps on the top of it. Can anyone tell me what they are? Based on the style I would assume the one on the left is the filling one and that's where I'd dip to check the level, however I'm not sure what the one on the right is for.

Thanks

 

[Hugh Jaleak]

Brass cap is the filling point, allowing Tanker Driver to attach the filling hose to the tank securely, and return to the vehicle to commence the delivery. The 4" Cap is for inspection purposes as I understand it.

 

[lostinthelight]

Brass cap is the filling point, allowing Tanker Driver to attach the filling hose to the tank securely, and return to the vehicle to commence the delivery.

May be ommited to cut costs on new tanks if oil isn't banned,? I bought oil for the first time in 5 years this year and the driver controlled the delivery from the tank by remote control.

 

[ChrisJP]

The plastic 4" cap on the right will easily allow a wooden dipstick to be inserted. Some tanker drivers use this aperture to fill the tank with a nozzle rested into the aperture, rather than bothering with unscrewing the metal cap and screwing on the delivery pipe.