New Viessmann 100-W boiler taking longer to heat radiators up than old cast iron unit
I have been using a Ideal Classic NF70 open balanced gas boiler for some 24 years without any problems occurring with something like 25kW input running 14 radiators via a Grundfos pump on speed 2 plus two Honeywell valves. This set up was installed when the house was built and would just about cope when all 14 radiators were fully on.
We decided to replace the boiler with an up to date boiler after so many years of use. A local plumber installed a Veissmann Vitodens 100-W WB1B open vented system rated at 26kW after waiting three months for him to turn up.
Now it takes nearly twice as long to get the radiators heated up than the old boiler that of course fired up with full gas flow burning all the time and the new one cutting down the burn rate as soon as the temp reaches the pre set in the small bore stainless steel heat exchanger. Even set on a maximum of six on the front panel?
All the radiators have thermostatic valves fitted and pointed out to the plumber that there is a bypass valve set behind the copper tank in the airing cupboard at aprox a quarter of a turn open on a 180degree valve with only 15mm copper pipe attached to the normal 22mm piping to the tank and valves.
Once the radiators are eventually up to temp the bypass system gets very noisy and keeps me awake at night if I leave the central heating on. Should I install an auto balancing valve and replace the manual 15mm 180 degree unit that was fitted originally. I get the feeling that because the bypass valve is always semi open the modern burner straight away cuts down to a low setting as it sees the water temp from the bypass as up to temp?
Irony that the old cast iron boiler heated up the 14 radiators far quicker than the new boiler installed last month. Any help gratefully received as we seem to have gone backwards at the moment.
I have been using a Ideal Classic NF70 open balanced gas boiler for some 24 years without any problems occurring with something like 25kW input running 14 radiators via a Grundfos pump on speed 2 plus two Honeywell valves. This set up was installed when the house was built and would just about cope when all 14 radiators were fully on.
We decided to replace the boiler with an up to date boiler after so many years of use. A local plumber installed a Veissmann Vitodens 100-W WB1B open vented system rated at 26kW after waiting three months for him to turn up.
Now it takes nearly twice as long to get the radiators heated up than the old boiler that of course fired up with full gas flow burning all the time and the new one cutting down the burn rate as soon as the temp reaches the pre set in the small bore stainless steel heat exchanger. Even set on a maximum of six on the front panel?
All the radiators have thermostatic valves fitted and pointed out to the plumber that there is a bypass valve set behind the copper tank in the airing cupboard at aprox a quarter of a turn open on a 180degree valve with only 15mm copper pipe attached to the normal 22mm piping to the tank and valves.
Once the radiators are eventually up to temp the bypass system gets very noisy and keeps me awake at night if I leave the central heating on. Should I install an auto balancing valve and replace the manual 15mm 180 degree unit that was fitted originally. I get the feeling that because the bypass valve is always semi open the modern burner straight away cuts down to a low setting as it sees the water temp from the bypass as up to temp?
Irony that the old cast iron boiler heated up the 14 radiators far quicker than the new boiler installed last month. Any help gratefully received as we seem to have gone backwards at the moment.
