Outrageous Banging

Banger

Having a problem with a Slan Finn boiler. When the boiler starts up we get banging in the pipes. We have tried the standard fixes including changing expansion tank, lowering pressure and temp. The banging seems louder than we would generally hear from expansion problems.

Rich_49

Is this

a new install done recently or did this problem just appear ?  A bit of background would be helpful to help

icesailor

Lower Pressure:

Why would you lower the temperature and also lower the pressure at the same time?

I'd be setting the pressure to over 20# and then lower the temperature to 140 and see what happens. You can do one or the other, but if you do both, how will you know which one is the problem if it stops?



Illogical Troubleshooting.

Banger

Slant fin remedies

added zone to existing. tried each fix one at atime

Rich_49

Zone valves

how many and what type of circulator is moving your fluid ?   Please try to tell us if this happens when all zones are opened or if only when some are open and some closed .  Did this happen before and got louder and worse and why did you add a zone ?  Your piping may be strapped and supported poorly where you can or cannot see , couple this with a single speed pump that is just right or oversized and when those valves close and the velocity changes in the open zones it can make a hell of a racket .  Bad support and strapping alone can cause this issue but if it got louder when you expanded the number of zones and added a valve makes it suspect .  A Delta T pump can lessen or eliminate this problem then if it persists continue searching . The new pump is a nice addition anyway and will improve the wire to water efficiency and fuel consumption somewhat .  You can only fix one thing at a time as it seems you already know .

earl burnermann

where do you live that you are using heat in June?

Are there any calls for heat in your home at this time of year?

Are you using circulators or one circulator and multiple zone valves?

Do you have a indirect water heater that uses a zone valve to supply boiler water to the appliance during a call for hot water?

If you are using zone valves, what brand and model are you using?