Capping off a tankless hot water heater

Hey_Obie

I have a Burnham oil boiler with tankless hot water heater. I have installed an indirect hot water tank and want to eliminate the tankless.



My plan is to blow the water out of the tankless and then cap the two pipes. I figure with just air and a little water, the pressure will not be too extreme.



Is there anything wrong with my plan?

JStar

I wouldn't.

Why take the chance of capping the lines? They won't do any harm if you leave them open.

Charlie from wmass

Nice pipe bomb

I cap the lower pipe and install a pressure relief valve on the higher tapping. If the tankless is not compromised all ready then cap the lower one and leave the upper one open.

Ron Jr._3

Why not

leave the coil connected as a backup ?  Keep the valve off to the inlet of the coil . That's how we pipe our indirect heaters into an existing boiler . Very , very rare to see a coil leak internally . Very , very common to see an indirect leak though .

Hey_Obie

Thank you.

I will cap the lower and leave the other open

Hey_Obie

That makes sense as well

I am going to add a Cold Start controller so I can add outdoor reset. I am not smart enough to figure out if that will work if I have tankless. I don't think that works, because the boiler could go cold and the hot water would be cold.

TonyS

try using one of these

http://www.beckettcorp.com/Product2/productdetail.asp?detailid=35

It has a heat manager built in and it can  easily be changed from triple acting to cold start. Also the price is very reasonable.

Hey_Obie

TonyS - Thanks for the info

I checked out the AquaSmart and I really like the simplicity and the price. Have you been happy with the results and reliabilty of the unit?



I have a Taco ZVC406 with DHW priority. To get outdoor reset working on the ZVC406 with TACO components, I have a real mess. I didn't know that I should have ordered ZVC406-EXP (it has a plug in port for the outdoor reset module). So they told me I have to buy a SR501-EXP and connect it to my ZVC406. Then I can connect the PC700 (reset control) to the SR501 (egad). The SR501-EXP is $100 and the PC-700 is $275. So I would have to add $375 and hope I can get it all to work.



The AquaSmart is about $150 and I know I can just swap out my control and be off to the races. Thanks again a whole bunch



I have a question if you are familiar with the AquaSmart. I believe the old Heat Manager had two sensors. One for the boiler and an optional one for DHW. I think the Heat Manager used to take the DHW out of the calculations for outdoor reset if I am not mistaken. The AquaSmart, does not seem to care about DHW in its reset calcs. I guess, DHW is such a small factor in the winter, that it must be added into the reset calcs and does not affect anything. Does this make sense?



Mike

TonyS

I only have one installed so far

I was recently at a show in Hershey and was talking to the Beckett rep. Beckett has always treated me fairly so I purchased one. Worked well and was really a good value considering it serves as the aquastat and the Heat manager as a bonus.

The wiring schematics in the manual will show you how to connect the Indirect so it overrides the heat manager.

He also showed me a new sensor for the unit so it also serves as a low water cutoff, although that was still prototyped but coming soon.

Read the instructions well before installing, pay particular attention to the insertion of the temperature probe in the well. The ROI on this unit could easily be less than 1 heating season.