Temporary boiler bypass - do I need it?

[hmalib]

Hello,

I bougth a house and am redoing the heating system from baseboards to radiator panels with homerun manifolds (same concept as radiant heating but uses homerun manifold and radiator type panels instead of the baseboards).
I need to disconnect the current supply and return pipes from the boiler so that I can remove the old pipes and run new pipes (pex). This will take me probably more than a month to do so (diy).
My question is about what I can do with my boiler in the meantime. The boiler is the weil-mclain oil burner that is a combo boiler and tankless water heater. I need the tankless water heater to work but do not know if I can just shut off the valves for supply and return for the boiler's radiator piping. Or do I need to create bypas loop between supply and return on boiler? There should be water still in the boiler, except it won't be able to circulate
The model of my boiler is weil-mclain wtgo-3
If the thermostat is in off setting , teoretickly the boiler should not go on, only the tankless heater.

The quick question is:
Can I just shut off the supply and return valves on boiler's radiator pipes and then cut the pipes. Leave that cut until I am ready to reconect supply and return to the new manifold. Or do I have to create temporary loop between the supply and return for the time period? The work will take me probably about a month, so the boiler water would be not circulating for that long.

Thanks,

Henryk

 

[Mr_David]

Not sure how this is piped so I'm gonna guess. The boiler heats both radiant heat and for hot water at fixtures.
It is an on demand heater. With the radiant system isolation valves off you still have cold water coming into the heater and and when you open a faucet water can still floe through the heater. The heater should have a built in flow switch that detects the flow and allows it to fire off and heat the water.
If the radiant heat loop has a recirculating pump then your going to have to make sure that that is off while you are making repairs to the RH system.
The heaters has built in safeties so if there is water flow through the systems it should work.
Edit: I'm guessing the thermostat controls the recirc pump and if it's off then the the radiant heat system is off. It should be okay to turn off the valves and disconnect