new combi boiler advice

[craigibc]

morning,

I just picked up a combi boiler to replace an old boiler and hot water tank.

Try to figure out what from the old boiler I will need to use on the new setup.

Currently I have a circulator pump and also a AquaStat that connects to a controller on the gas line.

Will I need to move all of this over to the new Combi? I picked up a Nortiz CB199.

It looks like I should be able to keep the circulating pump in place but the aquastat and the gas line regualtor is a question mark. It looks like the reguator on the gas line has a small copper pipe going into the old boiler.

Advice!

Thanks,

Craig

 

[Jackfre]

Taht is a Korea boiler sold under license to Noritz and a number of other manuf here in the states. It has been in the market for 3-4 yrs. You should not require a secondary regulator, I am assuming NG here. Get a manometer and check the gas pressures and decide from there. I would suggest that you pipe your boiler with a primary secondary lay-out so your current circumstances may work on the house side. I don't know if the CB has an internal circulation. If it doesn't you will need a circulation for the boiler side of the P/S piping.

 

[yeldogt]

Pipe per the boiler instructions or you will have problems

Is the old a cast iron with a pump on the return ? What type of heat.


You are doing a very different set up vs what is there .. if CI

Aguastat on the gas line?

 

[craigibc]

It is natural gas. I did speak to the manufacturer and it has a circular pump built into it. Th e only thing I can see that they require is an expansion tank in the directions. I was hoping to get some insight from others...

 

[yeldogt]

It is natural gas. I did speak to the manufacturer and it has a circular pump built into it. Th e only thing I can see that they require is an expansion tank in the directions. I was hoping to get some insight from others...

There has to be some piping layouts.

What is you current boiler ...


A combi boiler is a boiler with the ability to heat DHW .. like an on demand.

They need to be sized correctly and the boiler has a pump ... because it needs a primary loop. The secondary goes out to whatever you were heating with the old boiler.

How did the old boiler heat the DH water

They need to be sized correctly

 

[craigibc]

The new boiler is a few BTU larger than the existing. 120k. It is a CB199NG from Nortiz.

The current setup is one zone valve/ circular pump that is wired to 3 different zones and it calls for heat when needed. It has a Aquastat on the incoming water line and a Bell Howell for the circular pump. The circular pump connected to the NG line.

See attachd

 

[yeldogt]

First -- you don't have a circulator on the natural gas line.

I can't see the boiler so it may be high or low mass ...

But -- you need a primary and secondary.

You may be able to have a single smart constant pressure pump and keep the zone valves.

The old boiler ran hot -- with hot return. each zone could call for heat and turn on the boiler and the pump.

There are many ways to sent these up ... what kind of radiation (baseboard). You can even do these with out door reset

How do you heat the water now?

 

[craigibc]

This is the old boiler

 

[craigibc]

Right now the circulator on the output of the water it connects to the aquastat and then a wire goes to the zones that connect to the thermostats and another wire to the boiler.

See photos above.

It is copper baseboard finned radiators.

 

[craigibc]

One wire goes from the circulator to the 3 zone temp sensors.