Combi Boiler System Installation Help

[Reicherb]

I'm

Not sure. Page 34 for water piping shows it on the supply. They usually are last though. I was thinking there might be a check built into the circulator that is messing things up. Does your gauge record pressure spikes with a tattle tail needle? In your picture the condensate is in that same area also. It'd be nice to make sure that it's water expansion causing the relief to trip and not something else.

Page 34 is domestic hot water. The pressure gauge in the boiler reads a few pounds higher than the external gauge. Neither seems to fluctuate much.

Your pressure is running 21 lbs? Why its floor heat? What air pressure is in the expansion tank cold system 100* f or less? How many gallons of water in the system and model and brand of ex tank? 30* td across boiler would like to see more flow 20* but its ok.

It's this tank.
https://www.supplyhouse.com/Amtrol-102-1-30-Extrol-EX-30-Expansion-Tank-4-4-Gallon-Volume
It was charged to 15psi when I installed it. The system has about 16 gallons of water.

 

[Reicherb]

I just stumbled across this.
https://www.supplyhouse.com/Weil-Mc...1MtC_DgnsXW4zPNXais6Llu43NM8I7xPgZ-h0XjLlb1ls
That seems to indicate by relief valve is in the right spot. which then leads to believe the check valve is my issue. Or maybe I just put too much water in the system.

 

[Sponsor]

 

[John Gayewski]

I just stumbled across this.
https://www.supplyhouse.com/Weil-McLain-383-100-060-AquaBalance-Easy-Up-Manifold-Kit-for-Combi-80-120-155-Boilers?utm_source=Facebook&utm_medium=catalog sales&utm_campaign=cross-upsell&utm_content=ntm&fbclid=IwAR1kMdUa987sDs1MtC_DgnsXW4zPNXais6Llu43NM8I7xPgZ-h0XjLlb1ls
That seems to indicate by relief valve is in the right spot. which then leads to believe the check valve is my issue. Or maybe I just put too much water in the system.

There's no such thing as too much water in the system it needs to be completely full. Your expansion tank only needs to have less than .5 gal. In capacity.

 

[Fitter30]

Relief valve should be set at 30 lbs. Valve make up water off to take the regulator out of the picture.

 

[John Gayewski]

I just stumbled across this.
https://www.supplyhouse.com/Weil-McLain-383-100-060-AquaBalance-Easy-Up-Manifold-Kit-for-Combi-80-120-155-Boilers?utm_source=Facebook&utm_medium=catalog sales&utm_campaign=cross-upsell&utm_content=ntm&fbclid=IwAR1kMdUa987sDs1MtC_DgnsXW4zPNXais6Llu43NM8I7xPgZ-h0XjLlb1ls
That seems to indicate by relief valve is in the right spot. which then leads to believe the check valve is my issue. Or maybe I just put too much water in the system.

The check valve should not be at the inlet of the pump. Check valves get fouled and can ruin your pump. I don't think it's a great idea to contradict the manufacturer's diagram, but the check should not be at the inlet like that.

I personally would move it. Maybe temporarily get rid of it and see how it performs.

 

[John Gayewski]

We also use swing checks not spring checks.

 

[Reicherb]

What is the risk of no check valve? I can't see how the water could flow backwards.

 

[John Gayewski]

What is the risk of no check valve? I can't see how the water could flow backwards.

Your secondary pump could push it backward.

 

[Reicherb]

Your secondary pump could push it backward.

How would I detect that?

Wouldn't that mean the check valve should be on the supply/output side of the primary loop?

 

[John Gayewski]

How would I detect that?

Wouldn't that mean the check valve should be on the supply/output side of the primary loop?

It stops the water really no matter where it's at, but I do think it should be over there, as I've been saying. It's just tough for me to contradict what the manufacturer has.

 

[Reicherb]

I took out the check valve and the pressure relief is no longer leaking. Everything seems to be working well. Should I leave it as is or install a check valve on the supply side?

 

[John Gayewski]

I took out the check valve and the pressure relief is no longer leaking. Everything seems to be working well. Should I leave it as is or install a check valve on the supply side?

If your happy leave it. If you start to notice flow where there shouldn't be put it on the supply side.

 

[Fitter30]

For some reason the built in pump and the spring check had to built pressure between them of off cycle over pressuring the relief.

 

[Fitter30]

For some reason the built in pump and the spring check had to built pressure between them of off cycle over pressuring the relief. Put a swing check on the supply side on a horizontal line just on the secondary loop discharge side of pump if it doesn't have a built in check. Install manual doesn't want one on the primary.

 

[Reicherb]

Put a swing check on the supply side on a horizontal line just on the secondary loop discharge side of pump if it doesn't have a built in check. Install manual doesn't want one on the primary.

Put it where?

 

[Fitter30]

Check on primary loop