heatmaker 9600 HWG thermostat housing

archibald tuttle

I've got two of these in service and the frigging thermostat housings have been dripping since the first year and the parts lists don't offer the o-ring separately.  I know there is a part number but their distributors don't seem interested in finding it for me - at least the several I checked with.



I know they know this, yet there has been no update to the parts list. Talked to them last year. Got a number. Called a distributor who said they would order it. They never got back to me and I've lost the friggin number and nobody feels like picking up the tech support line I've got for heatmaker. So, if you know the part number, I'd appreciate it.



All that said, da plummer frien says just get a thermostat kit and replace the thermostat. It's probably bad. $169 to replace a gasket seems pretty stupid unless there is some high degree of failure in these units. The biggest distributor of Heatmaker parts around here has one of these kits in stock but says its a slow mover and they hardly ever sell any. For everyone else its an order item.  So this tends to make me think that there are either a lot of failed themostats out there that need replacing, or they are robust and don't fail but it's the only way anyone has found of getting a new seal without fighting city hall. For the time being I just siliconed the old seal back in place but now I'm interest in whether the tstat really needs replacing.



The literature seems to suggest it is a 140 deg. thermostat. There is no written theory of ops I've found, but I'm guessing that it recirculates most water until the boiler heats to 140 deg. so you don't get a false trip of a low limit. but that is completely a guess on my part.



Of course the principal safeguard is a pressure differential measure across the pump that proves circulation. But maybe there is a low limit cut-off as secondary safety that would also indicate lack of circulation through the coil, to protect it from meltdown.



So, is there a way to monitor heat flux on start up that will indicate to me whether the thermostat is, or is not, functioning properly. (maybe i should be thinking the thermal imaging camera discussion although usually my testing amounts to taking various pipes in hand and holding on until they threaten to burn my fingers).



Thanks,



Brian

Unknown

O-rings,

are not hard to get but you need the measurements (with a Vernier).

Of course you`ll have to open it up again, but then you`ll have it.



Also, you can get small 2 probe temp measurement meters that will display the temps from the valve to you,,, should have these anyway if your in the biz.  :-)

archibald tuttle

thx also answered my own question

the gasket on the thermostat housing is a 10-266 .



the laars people insist it is on the commercial parts diagram they are working from but it sure is not on the parts list for the 9600 HWG that I downloaded from their site so that remains a mystery.



Yeah, I have a twin temp measure with pipe clamps. I use it for refrigeration all the time, but i'm so used to just holding the pipe and estimating by hand that I didn't even think of it. . .