Hi All, New to the Forums!
I am in process of re-piping hydronic system. System is 10 years old gv-6 series 2 boiler ( 153,000 DOE). Currently p/s piping with boiler loop done in 1 in copper and t's spaced 12 in apart into secondary system. secondary is a 2 in copper manifold parallel system with 1 circulator for indirect domestic heater piped in 3/4 in circuit. there are 6 other space heating circulator loops supplying fin tub radiators. each circuit about 20,000 btu 3/4 in copper.
problems are boiler short cycling frequently (average 4 min firing time) with a large delta t of 40 degrees. boiler set point is 200 degrees. otherwise system working well with plenty of hot water and comfortable room temps.
new scheme will have boiler loop done in 1-1/4 in copper pipe. and keep the 2 in secondary manifold.
Questions:
1. should we go to 1-1/2 boiler piping and what is best distance between copper t's to secondary loop?
2. should the indirect heater ( amtrol boiler mate whs- 60 ) be piped parallel into the boiler circuit or keep it in the secondary circuit as a separate zone. if put in boiler circuit should it have closely spaced t's or just parallel circuit? planning on using 1 in copper for this circuit.
3. should the boiler mixing valve be removed or plugged (per technical bulletin) since it might fail and then add an external mixing valve to keep the boiler return water temp above 140 degrees. if so would a ball valve work from supply to return or do you suggest a mechanical or motorized mixing valve?
4. with the short/frequent cycling can you suggest or recommend a buffer tank and size.
Is this necessary? the multiple space heating zones are micro loading. the house is well insulated and zones do not run for more than a few minutes each and seem to always be running one at a time.
5. it seems that the gv-6 is oversized for the house. house is 4500 sq ft in north east.
6. what is optimum delta t and duration of firing time for this boiler?
Thanks
any help would be appreciated.
this is the second re-pipe of this system. original plumber had circulators on return with all kinds of noise!
Anthony
I am in process of re-piping hydronic system. System is 10 years old gv-6 series 2 boiler ( 153,000 DOE). Currently p/s piping with boiler loop done in 1 in copper and t's spaced 12 in apart into secondary system. secondary is a 2 in copper manifold parallel system with 1 circulator for indirect domestic heater piped in 3/4 in circuit. there are 6 other space heating circulator loops supplying fin tub radiators. each circuit about 20,000 btu 3/4 in copper.
problems are boiler short cycling frequently (average 4 min firing time) with a large delta t of 40 degrees. boiler set point is 200 degrees. otherwise system working well with plenty of hot water and comfortable room temps.
new scheme will have boiler loop done in 1-1/4 in copper pipe. and keep the 2 in secondary manifold.
Questions:
1. should we go to 1-1/2 boiler piping and what is best distance between copper t's to secondary loop?
2. should the indirect heater ( amtrol boiler mate whs- 60 ) be piped parallel into the boiler circuit or keep it in the secondary circuit as a separate zone. if put in boiler circuit should it have closely spaced t's or just parallel circuit? planning on using 1 in copper for this circuit.
3. should the boiler mixing valve be removed or plugged (per technical bulletin) since it might fail and then add an external mixing valve to keep the boiler return water temp above 140 degrees. if so would a ball valve work from supply to return or do you suggest a mechanical or motorized mixing valve?
4. with the short/frequent cycling can you suggest or recommend a buffer tank and size.
Is this necessary? the multiple space heating zones are micro loading. the house is well insulated and zones do not run for more than a few minutes each and seem to always be running one at a time.
5. it seems that the gv-6 is oversized for the house. house is 4500 sq ft in north east.
6. what is optimum delta t and duration of firing time for this boiler?
Thanks
any help would be appreciated.
this is the second re-pipe of this system. original plumber had circulators on return with all kinds of noise!
Anthony