runaway CI Dunkirk

Fishmael

2nd attempt...grrrr...5 or 6 sect CI Dunkirk,given Honeywell's 8148 and 4006E...original prob is the 4006 is tripping,so we R+R the 8148 thinking we're all set...but not the result. It continues. Clues: on arrival the 4006 is set at 235 or 245(if there is a 245)and the 8148 was at 205 I think. I felt those were odd numbers.Set the 8148 at 180 and the 4006 at 205...uhhh,and it does it all over...more clues: audio FX like a gas water heater that has a bottom build-up of junk....pop..pweeoo.....and the customer says the last time it went down,a floor above it was making a lot of noise...but it's not air,and all the zones return hot...what am we missing? It's getting past the 8148. Why?

icesailor

Over heating?

I'm not sure what the problem is but, it seems that the 4006 is a high temperature manual cutout and it is tripping out on high limit. It was set to 245'.  The 8148 is the boiler temperature controller and is/was set at 205'. You reset the 4006 to 205' and the 8148 to 205'?

If the 8148 is failing and running high, the 4006 will probably keep tripping out on high limit. What does the tridicator temperature gauge read for temperature? I don't trust them but I have see quite a few 8000 series controllers go bad and they always start overheating. They won't usually both be bad. Turn the 4006 up and down and note where the click is. If that is correct, listen to where the click is on the 8148. If they differ, one is bad. Most likely, the culprit is the 8148.

Try a wider differential on the 4006. It can be 230'. If the problem goes away, replace the 8148 because it will not get better, only worse. And thermal lag/over temp. can easily be 25 degrees. That would cause the 4006 at 205 to trip out. It should be at least 230 IMO. For whatever that is worth.

Fishmael

yah,but.... (yahbuts live in the woods...)

OK ,wider diff, but the 8148 is now new,we switched it...( R+R....remove and replace,sorry..)...another clue...we couldn't get the thing to give us much more than 170 deg.  I also mistrust all tridicators ( shouldn't it be a bidicator?...or just a lying li'l' boiler gauge?...)  no,I was using a digital thermometer to check. Give me a nice Trerice anyday...intermittent unregulated gas pressures? what else is there?

icesailor

Dunkirks:

Fish,

Although they call it a "Tridicator", it really is your wished upon "Bidicator". There are only two needles. One for temperature and one for pressure and altitude/level of water above the gauge. If you have a tridicator gauge, and it reads 15 PSI gauge, the water level in the system will be 34.7' high.

I don't trust them either. And if the boiler is drained and it reads 5#, maybe it's 5" off, maybe not.

I have an infrared digital thermometer and it isn't always accurate.It depends on where I point the dot. I think that the 8148 is bad.