Spinflo gas grill, problem and solution.

[MoominPapa]

We have a spinflo midi prima gas grill and oven on board. These are fairly cheap and nasty things, built down to a price (and weight) for the caravan market, but it's done OK as our main cooker for a decade or so.

 

Slowly enough that we didn't notice it for a long time, the performance of the grill has been getting worse, and it finally got to a point where something had to be done. I expected that the problem was partial blockage, either of the jet,or the mixing tube, or both. The reality was different.

 

Having got access to the back of the device, I removed the jet and supply pipe. This is mounted on a bracket and shoots the jet of gas into the end of the long tube that runs up the middle of the grill and has holes to form the individual flames of the grill. The jet was clear, as was the tube. Then I noticed that the end of the tube was not in-line with the jet: it appeared to have dropped, so the jet was significantly closer to the top of the tube than it's centre. The tube and the expanded metal which is heated and glows red and a stainless heat shield are all mounted on two fittings which are attached to the underside of the top plate of the grill cavity. This top plate (in fact all of the cavity) is made of thin gauge aluminium and over the years it had distorted, I guess though the effects of heat and differential expansion of the steel gubbins mounted underneath it. Bending the plate to re-align the flame tube with the jet wasn't difficult; I used a pair of vice-grips on the rear fitting and just pulled. I sighted through the bracket for the jet to make sure I had the tube and jet co-axial again.

 

Result: complete cure!

 

Just putting this here, in case anyone has the same problem and wants the solution.  Beware that this requires breaking gas joints, so only attempt it if you're competent to do that safely and test them again afterwards.

 

MP.

 

[MtB]

4 hours ago, MoominPapa said:

Result: complete cure!

 

Fascinating, many thanks!

 

I too have had trouble with grills being pathetic. I fixed mine by fitting a new jet, one size up....

 

LOADSAGAS! 

[MoominPapa]

13 hours ago, MtB said:

 

Fascinating, many thanks!

 

I too have had trouble with grills being pathetic. I fixed mine by fitting a new jet, one size up....

 

LOADSAGAS! 

If I'd done that, and admitted it here, people would be predicting my imminent, fiery, death.  I'll bear it in mind for future enhancement, but given how flimsy the thing is, I think I'd be wary of increasing  the heat output too much.

 

MP.

[MtB]

22 minutes ago, MoominPapa said:

If I'd done that, and admitted it here, people would be predicting my imminent, fiery, death.  I'll bear it in mind for future enhancement, but given how flimsy the thing is, I think I'd be wary of increasing  the heat output too much.

 

MP.

 

Agreed, it's not something to do lightly. Flame picture and stability need to be maintained and yes there is a risk of all manner of things going wrong and the cooker manufacturer would understandably deny liability under such circumstances. Don't do it, is my advice. 

 

More pertinently, I occasionally encounter an old-format, non-condensing boiler where it fails to cross-light properly, with only small flames on the burner bars. The usual cause of this is a fine carbon-like deposit a few thou' thick on the inside face of the gas jet, virtually invisible and looking like a shadow, but reducing the diameter of the hole through it significantly (even though there is still an obvious hole). 

 

The fix for this I've found, is to dissolve the deposit away by boiling the jet in vinegar. Only takes a few minutes but this always restores the boiler to full performance, and the customers tend to be amazed having looked mildly sceptical when I explained the problem and seen what I did to fix it. 

 

Point is, it might actually be that the grill where I fitted a new jet might have also been suffering the same problem, and vinegar-boiling the jet might have restored performance too. 

 

I too have a Caprice (in a different boat) with a pathetic grill and also a pathetic oven. How it your Caprice oven? Mine oven fails to ever heat up beyond gas mark 4 so hopeless for making bread or anything needing a decently hot oven. It is my intention to dismantle it and try vinegar-boiling the jets to see if that helps. 

 

 

[MoominPapa]

20 minutes ago, MtB said:

 

I too have a Caprice (in a different boat) with a pathetic grill and also a pathetic oven. How it your Caprice oven? Mine oven fails to ever heat up beyond gas mark 4 so hopeless for making bread or anything needing a decently hot oven. It is my intention to dismantle it and try vinegar-boiling the jets to see if that helps. 

 

 

I'm not the oven user on this boat, so I can't give a definitive answer, but it does certainly make bread OK, and had cooked a complete Christmas dinner (slowly) on more than one occasion.

 

The main problem we've had in the past with the oven is that the burner is very close to flame-lift. Even a marginally over-pressure regulator is enough to hit the problem as we discovered when the thing was installed. An new reg fixed it, but anything even very slightly over 37 mbar and half the burner blows itself out. This may cause you problems in your attempts in increase gas flow.

 

MP.