Add 4th zone for indir HWH to boiler not pumping away?

D107

D107

25yr old boiler works fine but I want to hook up HWH

Have a gas-fired 1981 weil-mclain Model CGM-7P1 Series 7 gross input 210K/Output165K BTU Net 143K Btu boiler. In three zones, not pumping away, no bypass, no LWCO and the undersized compression tank is in wrong place--at start of supply line. Boiler works fine.

My current direct HWH is 17 yrs old and gurgling. Like to install an indirect; boiler capacity no problem as it is oversized. I wonder if due to the aforementioned conditions (see attached photos) would there be any likelihood of problems with adding the fourth zone? I would probably get a size 30 or 60 compression tank. I'd rather add an indirect than a direct, even though I know that I'll be paying a little extra later when I repipe the indirect to a new modulating or MOD CON boiler when I do that in a few years.

Ted_9

loan

get the money via loan or what ever and change out the whole system. repipe pumping away, indirect etc. do it this summer. its a better investment than that car.

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Reed

indirect

I agree with Ted. If you can get the money to change out system do it! If not I see no problem with adding fourth zone for indirect. By looking at the picture you sent the supply header looks to be 1" and the return headeris 3/4". If you add the fourth zone I would increase the return header to at least 1" and it looks like your expansion tank is a 30 .

D107

Expansion tank is actually a 15; really too small.

When I manually raised the aquastat from 170 to 180 degF in Dec the expanded water blew the boiler relief valve.

You're right about replacing the whole unit of course. Trouble is basement and near boiler piping really needs to be repiped--as you say the 3/4 should be 1", and I believe there is no separate return manifold just a supply, so things move a little slowly. Guys who set this up obviously were not wallies.

Then I have to separate out a new zone for a porch over slab. Plus basement not sealed/insulated properly and rest of house is old CI triton rads but basement is baseboard which loses heat so fast boiler cycles almost every 15 minutes.

I guess whatever the aforesaid conditions a new modulating atmospheric and indirect would save me hundreds a year right off the bat, and the other things could be done later.

Thanks,

David

Unknown

We installed quite a few

indirect heaters this year to existing systems with the circs on the return manifold . Almost every job we had the indirect circ pumping away from the boiler and expansion tank . No callbacks on those jobs so far ......

I would highly recommend a multi zone control with priority for the indirect . You can use that control again on any new boiler you choose .

What brand expansion tank is that ? It looks like a domestic water tank , and the equivalent size of a Extrol 30 ?

D107

Expansion tank manufact. says 'Water Systems Division\"

Ashland City, TN from around 1981. Precharge is 12, and Max working pressure 100. Since model number is ET5 I assumed it was a 5 gallon equiv. but maybe not. Don't know if this company is Amtrol's parent or another brand.

I've had two fine Wallies pros down here (north of NYC) in Oct who made their recommendations but now that season is ending, I'll have to look seriously at what I can do. Other house projects going on so it gets a little crazy. Heat loss calc is currently being done--hoped to have house sealed better before getting new boiler...........

Thanks,

David

D107

so it's OK to have return AND away pumping on same boiler?

meaning, as you said the circs are on return side and the indirect hwh circ is pumping away? Never heard this was done but I guess it is....