Bloody Rayburn!

Help! I can't get my old Nouvelle oven up to temperature. I've cleaned the filters, the flue was swept a couple of weeks ago and she was cleaned out under the hotplate then with the oil ways cleaned and new wicks. She's running with a blue flame in the burner box (the sort with three lighting holes toaster type?) but it doesn't matter whether the knob is turned to max or just on 1 she stays at 100 and won't budge. I've put the low and high fire rate up a bit as she's breathing better but nothing is changing. She hadn't had her flue done for years so I guessed flow rate may have been turned down to compensate for the flue being coked up. Other half wants to get rid of her as it is and at the moment she's playing right into his hands! The boiler side is working fine so I don't think it's oil flow problems up to the valve otherwise that side wouldn't work or would it? I know Nouvelles are a pain in the butt and are pretty obsolete but I want to keep her going for a bit longer. I'm hoping to get a more up to date model when we get the kitchen done.

Have you operated the manual lever on the thermostatic top?

Yes, it's on manual because it won't work at all otherwise. She's managed to crawl up to 150 on 6. That's taken since 1pm yesterday! It must be starvation but I don't know where. She's still running a blue flame on the cooker side and the boiler is cutting in and seems to be working fine. I have a wood burner linked into the heating so the boiler doesn't have to work hard if at all sometimes. Last night it only cut in a coupe of times so it wasn't taking oil from the cooker side. I take it the oil valve is the same principal as a carburettor? If so I know how to strip one of those.

If boiler works, then fuel supply is not the problem. Did you check the oil depth after replacing the cooker burner? Did you fully clean the oil feed tube and elbow? If the depth is O.K. (about 6-8 mm on the outer channels) , then it may be down to a blocked metering column in the OCV. Remove the thermostatic top, undo the three screws and remove the top. The metering column is the brass tube with a stainless hat that sits under a spring in the outlet pipe. Lift it up and release the spring, withdraw from the outlet pipe and clean out the slot in the side, preferably with something like a bristle from a nylon brush. A metal blade may open it out too much. Replace it then check the flow rates as stamped on the data plate, at the burner connection. When correct, reconnect and check the burner oil depth and level. Reassemble the burner shells and relight.

When I serviced her the levels were ok and the oil feed tube was taken off and cleaned through so I'll have a go at the OCV. I had heard that there is biofuel mixed in the oil these days so maybe it's got gummed up, she's getting coked up a lot quicker than she used to. I've always done the interim service on her but now I'm having to do it all as my engineer has retired and nobody else will touch her. Last few times, her oil channels have been really bad before the scheduled service. Having seen the state of carbs after being left for a month or so on a bike I wouldn't be surprised as well, the biofuel in petrol is causing all sorts of problems too. The OCV sits with oil residue all summer when she's out. I lit her in October so there may just have been enough of a gap then and now it's closed up enough to slow the rate. Thanks for your help!