Sort of Urgent Question about TT Boiler and Smart 40 tank...

Javelin

Dear Heating Pros,
Of course this happens at the start of the Holiday weekend!
Earlier tonight we notice no hot water.. sort of odd. I go take a look at the boiler and the add-on DHW tank SENSOR (not the switch that comes default) doesn't look like it's reporting any tank temperature. So I remove it from the well and notice that parts of the wider well (where the aquastat usually goes) is a bit wet. Not sure if it was condensation from pipes above or what, but not a lot of water.. just an ounce maybe... but thought maybe that shorted something out?

So now, I still had the original SWITCH coiled up, so I removed the SENSOR and put the switch back down the well, put the thermostat in a middle setting or so, and hopefully have some heat for morning showers. Seems to fire ok and produce hot water.

But now, of course I'm nervous.. what if that ounce of water somehow messed up the aquastat/themorstat? DOes that mean that the boiler could fire indefinitely if the switch doesn't work? I have the T&P relief properly installed on the tank, but obviously don't want to use it! It's supposed to pop at 210 deg, since my boiler DHW supply temp is 180deg and my tank is set to 130deg, there should never be any danger right?

I mean even if the aquastat malfunctioned, and the boiler continued to supply 180 water to warm up the tank, the tank will never go above that right? Never blow the T&P and/or blow up through my roof!

Just want to make sure that it's safe to use the switch until I can get a replacement sensor.

Please advise - just need to get it squared away ASAP.

Thank you all so much in advance!

Jay

Javelin

Sorry - Also forgot.. Is it usual for these SENSORs to go bad over time? Is there a way to test/fix or do I just order another one? Thanks again!

kcopp

You are going to want to babysit it just to make sure the temp is right. T&P will not blow off. Watch you water temps though.
This would also be an example of where a mixing valve on the indirect is a good idea.
Yes sensors go bad. You can use an ohm meter to see if it working right but 99% sure its bad.
I am wondering if the well if starting to leak.... very rare.

Ironman

What boiler do you have? I'm gonna assume a mod/con since it could take a sensor input from the tank.

If that's the case, the boiler should show a fault and possibly lock out if the sensor gets out of range.

Also, there should be a tempering valve that conforms to ASSE 1017 standard at the outlet of the tank to protect from scalding should an aquastat fail.

The sensors vary in range, but most are 10k ohm NTC thermistors. That means that the sensor would have a resistance of 10k at 77*. But each sensor's value is determined by the BOILER manufacturer, not the tank. And not all use a 10k NTC.

kcopp

Ironman said:

What boiler do you have? I'm gonna assume a mod/con since it could take a sensor input from the tank.

If that's the case, the boiler should show a fault and possibly lock out if the sensor gets out of range.
..............................................
Thread title has it as a Triangle tube boiler. Probably a Prestige.

HVACNUT

Can't stand those bladder tanks. Lifetime warranty for a reason. You'll spend your lifetime replacing them.

Javelin

Thank you all.. The boiler is a TT Prestige Solo.. I'm going to go put in the switch and babysit it while it heats up now. There IS also a hot water mixing valve.

I'll doublecheck the dryness of the well, and probably order another sensor this week. Thank you!

Just for my own information, can you use an indirect tank that is from a different manufacturer than the boiler? This is my second problem with the indirect tank in 4 years. If/when it ever comes time to replace it, maybe I'll go with a different brand other than Triangle Tube?

Thanks!

kcopp

You can use whatever brand indirect w/ just about any boiler. I have had pretty good luck w the smart tanks.

Robert O'Brien

The well is leaking

Javelin

Sorry. .one more question.. Between getting a new SENSOR for the tank or getting a better aquastat switch (someone previously recommended a Honeywell aquastat with a better differential than the TT factory one:)

http://www.supplyhouse.com/Honeywell-L4008A1015-High-or-Low-Limit-Remote-Bulb-Aquastat-100-240F-5-30F-Adj-Differential-5483000-p

What is the better way to go?

Thanks!

Robert O'Brien

Javelin said:

Sorry. .one more question.. Between getting a new SENSOR for the tank or getting a better aquastat switch (someone previously recommended a Honeywell aquastat with a better differential than the TT factory one:)

http://www.supplyhouse.com/Honeywell-L4008A1015-High-or-Low-Limit-Remote-Bulb-Aquastat-100-240F-5-30F-Adj-Differential-5483000-p

What is the better way to go?

Thanks!

It's bad because it's wet. It's wet because the well is leaking.

hot_rod

If it's 4 years old, just replace the well, and sensor.

Javelin

Thanks Robert... If the well is leaking, obviously I realize that's not ideal, but can I continue to use the auqastat? I pull out the probe this morning and it seemed pretty dry itself, but there was another ounce or so of water in the bigger well area - seemed to be coming from the spongy insulation... (see attached pic.)

So now what? I pulled the aquastat knob away from the well (to make sure it stays dry), but the actual bulb that's down the well pipe seems to be functioning as intended (called for and shut off heat based on knob setting).

Would the well be something that's covered under warranty? Is it something I can replace? What would cause it to leak? Is it dangerous to keep using a leaky well with the switch that came with the tank?



Thanks,
Jay

Javelin

By the way.. for what it's worth, this was a warranty replacement tank that was installed in October 2016. The previous tank was shot due to a small crack in the hot water pipe nipple. FYI - just saying - not sure it's relevant or not. I've been reading other threads.. could water supply/quality/minerals be the issue for the bad well? I'm in Philadelphia, PA.

Thanks! (yet again)

hot_rod

If the insulation around the tank is wet, either a tank leak, or a leak at one of the threaded connections.

Zman

The wells on those flood with any water that ends up on the top of the tank. I would take a close look at the other water connections in the area. It is more likely the leak is coming from another source.
I would not switch over to a different aquastat. Just get another from triangle tube.

STEVEusaPA

Javelin said:

By the way.. for what it's worth, this was a warranty replacement tank that was installed in October 2016. The previous tank was shot due to a small crack in the hot water pipe nipple...

Thanks! (yet again)

If it failed, that's a pretty common place. I would thoroughly check the nipples into the tank (under the cover) for a leak. Your hot water nipple, barely in the photo, looks like it has something on it.
I'd hate to see you replace the well and the control only to find you have an unrepairable leak.
I would also stick with the factory spec'd aquastat.

HVACNUT

Weil McLain stopped using the TT (Phase 3) tank because of the constant problems and eating warranty replacements. I would recommend a standard coil HE tank or a Turbo Max.

Javelin

Thank you all.. Zman, I think you hit it.. I took a further closer look and isolated different areas with some paper towels to check for drips/moisture. It seems that my mixing valve is no good... it has some calcium? buildup or something and it's no longer easy to turn/adjust. I think there is a VERY small leak coming from there when there is a hot water draw. I have an order in for a new mixing valve, and I'll be sure to tighten everything up again.

The tank seems to be functioning for the time being with the original TT aquastat - but I'll order another SENSOR also, as it seems that's more precise and the way to go.. Right?

Best,

Jay

Jean-David Beyer

I have a W-M 40 gallon tank (made by TT) that was installed at the same time as my Ultra-3 W-M mod-con. Mid 2009. Some years after installation (2015?), the P/T valve blew off continually. It turned out that the aqua-stat in the well of the indirect failed demanding heat, so the boiler started pumping 195F +|-5F water into the outer tank. This was enough to open the P/T valve on temperature. Glad the valve worked.

Otherwise, I have no problems with it. I do run the indirect at 140-160F with a Caleffi temperature control valve between the indirect and the rest of the house. That aquastat (the old one and the new one) has a differential of about 20F, which tells me that everyone needs a temperature control valve at the output.

I used to know where I could get well type thermostats that had a differential of about +|- 0.5F, but I do not think it would be a good idea to use one in this situation.

Zman

Javelin said:

Thank you all.. Zman, I think you hit it.. I took a further closer look and isolated different areas with some paper towels to check for drips/moisture. It seems that my mixing valve is no good... it has some calcium? buildup or something and it's no longer easy to turn/adjust. I think there is a VERY small leak coming from there when there is a hot water draw. I have an order in for a new mixing valve, and I'll be sure to tighten everything up again.

The tank seems to be functioning for the time being with the original TT aquastat - but I'll order another SENSOR also, as it seems that's more precise and the way to go.. Right?

Best,

Jay

I would use the TT sensor....