I have a Viessmann Vitogas 100, installed about 17 years ago by a previous homeowner. It also is the boiler for hot water, so it runs all summer in hot water only mode. I’ve turned the heating component back on, but it’s not working properly. It would appear the circulation pump stops working. It is a Grundfos UP 36-64 F.
Here’s what I’ve observed.
I come home or wake up and the house is below temperature and the boiler is cold. The system is not calling for heat, but should be. The hot water tank is below the set temperature. (When in hot water only mode the system behaves fine)
I power cycle the boiler, and it starts up and heats the boiler and calls for heat. The circulation pump starts and everything works. Hot water tank starts heating. I goto bed, leave, do whatever and at some point I come back and the house is cold. Repeat.
I have two of the pumps, one for hot water to circulate through through the Vitocell, and one for heating. The Vitocell pump has a light that is perfectly solid when it runs. The heating pump light isn’t as bright and flickers a bit. However it’s done this for 4 years that I’ve been in the house. When it’s flicking, it’s getting 117-120V, the same that is coming into the wall mounted control unit.
I ran a relay test this morning and it comes off and on as I test the system.
Part of my problem is the house is getting knocked down in the spring for a new build so I’m hesitant to spend money on this system.
Interestingly while typing this the system shut off the gas and heating cycle despite the house not being up to temperature. About 20 seconds later is has started up again. Boiler is going up but not calling for the pump yet. About 2 mins later the system is calling for hot water circulation pump.
I Went to the remote control panel, it has the up arrow symbol so I believe it is calling for circulation but the main unit panel is not showing the same up arrow (I’m also unable to find all the symbol meaning in ny manual so may be confused on what it’s calling for) and the circulation pump is not running.
Here’s what I’ve observed.
I come home or wake up and the house is below temperature and the boiler is cold. The system is not calling for heat, but should be. The hot water tank is below the set temperature. (When in hot water only mode the system behaves fine)
I power cycle the boiler, and it starts up and heats the boiler and calls for heat. The circulation pump starts and everything works. Hot water tank starts heating. I goto bed, leave, do whatever and at some point I come back and the house is cold. Repeat.
I have two of the pumps, one for hot water to circulate through through the Vitocell, and one for heating. The Vitocell pump has a light that is perfectly solid when it runs. The heating pump light isn’t as bright and flickers a bit. However it’s done this for 4 years that I’ve been in the house. When it’s flicking, it’s getting 117-120V, the same that is coming into the wall mounted control unit.
I ran a relay test this morning and it comes off and on as I test the system.
Part of my problem is the house is getting knocked down in the spring for a new build so I’m hesitant to spend money on this system.
Interestingly while typing this the system shut off the gas and heating cycle despite the house not being up to temperature. About 20 seconds later is has started up again. Boiler is going up but not calling for the pump yet. About 2 mins later the system is calling for hot water circulation pump.
I Went to the remote control panel, it has the up arrow symbol so I believe it is calling for circulation but the main unit panel is not showing the same up arrow (I’m also unable to find all the symbol meaning in ny manual so may be confused on what it’s calling for) and the circulation pump is not running.
