Peerless WBV-03-110-WPCT cold start?

Rickoo

I'm converting from a tankless coil to an indirect. This boiler is 23 years old and the only time its gone cold is during a power outage (very infrequently) or the few times the system needed repairs that required shut down.

Should I expect any issues when the boiler will now be running cold start with the indirect?

SuperTech

I wouldn't worry about it.  I've converted plenty of WBV Peerless boilers to cold start without issues.  If anything, you might have the automatic air vents leak when it cools down.  But if they leak that's a good indicator that they needed replacing anyway. 

STEVEusaPA

When they (you) redo the piping, pipe in a thermostatic 3 way (or 4 way) mixing valve to protect the boiler from low water temperatures. Change the aquastat to a modern one, enable circulator hold off.
In reality, you're switching to warm start. The boiler probably won't go completely cold. Your boiler will most likely fire 2 or 3x a day for 5-10 minutes with no usage, just to recharge the indirect (depending on size).

Rickoo

My plan was to run the indirect at 140 degrees and install a mixing valve between hot/cold to adjust the domestic water to 120 or so.

How would a mixing valve be used to prevent the boiler from going cold? The indirect is a 45 gallon HTP Superstor ultra.

I'm using a Hydrostat 3250 plus

Any other suggestions are certainly appreciated!

STEVEusaPA

The mixing valve on the boiler piping is to prevent condensing from extended run times of low temperature return water.

Rickoo

Thanks Steve. Wondering how important this is. If left out and the boiler is having condensing issues will it be easy to detect somehow?

Any chance you could link a good diagram that shows where to pipe a mixing valve in?