After spending a lot of time researching boilers I came down to a final choice between either the Worcester Bosch 38CDI Greenstar Classic, or the Vaillant ecoTec plus combi 837 for my mother’s 1-bathroom, 3-bedroom house with a shower and no bath, and just herself as the occupant.
But I was dismayed to be told by WB technical dept that the minimum flow rate through the boiler needs to be 3.5 – 4 lit/min before the boiler fires to warm the DHW. That’s a huge flow rate, relatively, isn’t it? Less than that and the water in the taps and shower come out cold.
The full flow rate for the DHW with these boilers is around 16 lit/min, so this means that the flow has to be at least a quarter of this rate just for the boiler to fire!
Does anyone know whether this is typical of combi boilers? I have just emailed Vaillant to ask what their equivalent min flow rate needs to be for the ecoTec plus 837, but I fear their answer is going to be similar to WB's.
I had thought a combi would be the ideal choice for the circumstances, but am reconsidering now if it means every time she wants hot water she must run the taps fast. Could this be a problem in practice, or am I worrying unnecessarily?
Any advice would be greatly appreciated.
But I was dismayed to be told by WB technical dept that the minimum flow rate through the boiler needs to be 3.5 – 4 lit/min before the boiler fires to warm the DHW. That’s a huge flow rate, relatively, isn’t it? Less than that and the water in the taps and shower come out cold.
The full flow rate for the DHW with these boilers is around 16 lit/min, so this means that the flow has to be at least a quarter of this rate just for the boiler to fire!
Does anyone know whether this is typical of combi boilers? I have just emailed Vaillant to ask what their equivalent min flow rate needs to be for the ecoTec plus 837, but I fear their answer is going to be similar to WB's.
I had thought a combi would be the ideal choice for the circumstances, but am reconsidering now if it means every time she wants hot water she must run the taps fast. Could this be a problem in practice, or am I worrying unnecessarily?
Any advice would be greatly appreciated.