Tankless can't keep up! Where to hook-up for de-scaling?

[jbeebe]

Hi everyone, I appreciate your time in advance.

I'm running a TriangleTube natural gas tankless heater which heats my domestic hot water and baseboard heat. After a few minutes of running the shower the temp of the water begins to plummet. It happens at all other locations in the home, just takes longer due to the lower flow rate I suppose.

Here you can see that i'm not showing any error codes and the water temp is nice and high:



The temp will drop from 120>>88F after ~10min. It will do this even with the heat and all other water demand off.

I'd like to descale the heat exchanger but it looks like the installers didn't install any service ports. I have two hose spigots, but i'm not sure if I can hook up to them to pump vinegar through. Here's one spigot that is on the line coming out of the bottom of the exchanger:



And here's the other spigot on the line coming out of the small tank:




Here's a picture of the bottom of the unit:




It's been ~1yr since i've cleaned the electrode and done the other "routine" maintenance items. I think it's done this before, just not significant enough for my wife to complain about it so much until now, ha.

Where should I start? If I were to clean out the exchanger, how should I hook up the pump?

Thanks!

 

[breplum]

Not necessary to 'descale' and not actually true "tankless".
It is a "combi" boiler and does not have a tortuous style heat exchanger.
The hose bibbs are for startup purging.
I don't know TT equipment beyond that, sorry.

 

[MrInfoPhilly]

this is Why I prefer hot water TANKS..., Whats the BTU size of the tankless? maybe it's inadequate

 

[jbeebe]

ahhh thanks for the knowledge guys.

It's a TriangleTube Prestige Excellence rated at 86,000 BTUs

 

[TomFOhio]

Look up on google boiler flushing valve kit. They normally come right out the bottom of the boiler on the two
in and out nipples. Alot of companies don't install them to keep the price down.

 

[kiwi_outdoors]

it looks like something designed for a single locaton - not a whole house

 

[GReynolds929]

86,000 btu is pretty low for a combine unit. Depending on ground water temp it's gonna have a tough time keeping up.

 

[jbeebe]

Thanks guys,

That makes sense, it normally does fine in warmer months when the incoming water temp is high but in winter when the water is 40F it just can't keep up.

The previous homeowner had it installed, so I can't take the "credit" for this one. It's a 1300sq/ft house with baseboard radiators in every room and 1 full bathroom.

Looks like I'll just tell the wife to take quicker showers!

I appreciate all your help everyone.

 

[GReynolds929]

“Looks like I'll just tell the wife to take quicker showers”

hahahaha, ill be prayin’ for ya lol.