Thermecon 40/60. Noise, then breakdown.

[DaveJames152]

A couple of months ago my boiler, a Thermecon 40/60 developed a noise that sounded the same as one I had first heard a few years ago. That resulted in the oil pump seizing up due to an oil leak. The oil had washed away the bearing grease. The pump was renewed, and all was well.
This time it seemed to be the same fault. When the engineer had done his work, we were told that another new oil pump had been fitted. The heating worked once more, and we were almost happy ! The problem was, I came home to find the same noise. He had charged a fee that I am too embarrassed to relate. (I was at work during this). Yesterday it broke down again. Suffice to say, I am ready to fix it myself. I restore vintage cars, and feel this should be within my abilities with your help. Waffle over...
The red lockout light is on, and when it starts the cycle, all I hear is a loud hum. I'm guessing it's seized again. What's my first step ?

 

[Tibbot]

I restore vintage cars, and feel this should be within my abilities with your help. What's my first step ?

Why is it so many think their trade makes them competent at heating then have to ask at the first hurdle, as here.

Anyone can change a pump. It's the instruments and commissioning procedures that count.

 

[DaveJames152]

Did I say anything to suggest that I think I am competant at heating ? I don't think so. That's why I'm asking for help on a forum.

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[Burnerman]

Only a hum often means that the motor doesn't know which way to spin, due to a faulty capacitor. Other hums do indicate seized pumps though, which doesn't seem to be the case here!
Easy enough to bench test the motor (look for 3000 rpm near enough), the bearings should be smooth to turn (they howl when worn) and the pump should be smooth to spin too.
If applicable, check the coupling between the motor and the fan / pump at the same time.
John

 

[oilhead]

If you've had a pump replaced and it is a monoflame burner, then it is probable that the motor has had the bearings damaged by the leaking oil. Take the pump off the motor and see if the motor turns, and if it does, is it noisy?
Easy to change, but you need to check combustion after the job is done.

 

[DaveJames152]

Many thanks for your replies. As luck would have it, I have a capacitor tester. (I'm into old radios) So I can have a look at that. I shall take the pump off in the morning as suggested, and see what turns !
I would like to invest in a combustion tester. If you have any thoughts on something suitable. It's only going to be used about once a year, but it obviously needs to be accurate enough to do the job !
Thanks again.
Dave

 

[Boilerman2]

When we change a leaking oil pump on a burner with a close coupled oil pump, we recommend that a new motor or bearings are fitted as the problem you are experiencing often occurs very soon after the pump is replaced - if doing it your self a new motor would be easier to do you can get a new one from Anglian Heating components at Wymondham.

 

[Burnerman]

To set up your burner correctly, you will need a pressure gauge to set the pump belivery pressure....at around £25 or so they are affordable.
However, when you venture into flue gas analysis then its a different story. They are expensive to buy new (although basic ones aren't too bad) but they need to be calibrated regularly.
I thought I was being clever when I bought one from a pal -it lasted 6 months then packed in. I sent it away for repair and calibration and the end bill was £160 See what I mean?
A smoke pump is also essential as the emissions have to be pretty clean before you dare plug the gas analyser in.
Personally, I'd get Mr. Oftec to set the system up for you.
John