Trying to get my mind around understanding the design constraints of modern modulating boilers.
I have a home brewed system where each room (apart from the toilet which has a thermostatic valve) has its own room stat and associated heating profile with specific temperatures at different times of the day depending on the day, season, outside temperature or unoccupied. There is no overall house thermostat. The radiators are fitted with 24v thermally controlled valves. Hot water is controlled just like a radiator.
There are 12 radiators of which only 7* are typically ever in use and even then at totally different times during the day, there are many times when only one radiator is open and that radiator may well be below the minimum rating of the boiler 3.9kw in my case.
Kitchen* - 1kw plus 2kw , Dining room* - 1.3kw, Lounge* - 2.8kw, Bed1* - 1.5kw, Bed2 - 1.1kw, Bed3* - 0.9kw, Bathroom* - 0.87kw, Toilet - 0.3kw, Study - 2kw, Workshop - 2kw, Sun Lounge - 1.5kw, Hot Water 3.2kw. As you can see the boiler will spend most of it's time running at less than the minimum rating.
The Kitchen plinth heaters are currently on a permanently open connection with the power to the fans controlled when heat is required this provides a bypass function for the boiler which is not strictly needed as the boiler is never activated unless a valve is open and in the interests of economy will like to control as per the other radiators.
With modern modulating boilers is there any reason why only the burner would be modulated say down to whatever heating is required even as low as 1 or 2 kilowatt and the pump not be modulated at all just manually adjusted to ensure adequate flow through the furthest and highest radiator say in a three story house.
My current boiler an Ideal Vogue S18 (running at it's maximum temperature of 80 deg) does not seem to be coping with this setup at all well, 4 of the radiators are fan assisted and getting sufficient flow through them is proving problematic. My 35 year old cast iron sectional boiler worker perfectly, is this a case of modern is definately not better.
What impact might this be having on the boiler.
Is this the case that I have made my system too sophisticated for the boiler to handle.
I have a home brewed system where each room (apart from the toilet which has a thermostatic valve) has its own room stat and associated heating profile with specific temperatures at different times of the day depending on the day, season, outside temperature or unoccupied. There is no overall house thermostat. The radiators are fitted with 24v thermally controlled valves. Hot water is controlled just like a radiator.
There are 12 radiators of which only 7* are typically ever in use and even then at totally different times during the day, there are many times when only one radiator is open and that radiator may well be below the minimum rating of the boiler 3.9kw in my case.
Kitchen* - 1kw plus 2kw , Dining room* - 1.3kw, Lounge* - 2.8kw, Bed1* - 1.5kw, Bed2 - 1.1kw, Bed3* - 0.9kw, Bathroom* - 0.87kw, Toilet - 0.3kw, Study - 2kw, Workshop - 2kw, Sun Lounge - 1.5kw, Hot Water 3.2kw. As you can see the boiler will spend most of it's time running at less than the minimum rating.
The Kitchen plinth heaters are currently on a permanently open connection with the power to the fans controlled when heat is required this provides a bypass function for the boiler which is not strictly needed as the boiler is never activated unless a valve is open and in the interests of economy will like to control as per the other radiators.
With modern modulating boilers is there any reason why only the burner would be modulated say down to whatever heating is required even as low as 1 or 2 kilowatt and the pump not be modulated at all just manually adjusted to ensure adequate flow through the furthest and highest radiator say in a three story house.
My current boiler an Ideal Vogue S18 (running at it's maximum temperature of 80 deg) does not seem to be coping with this setup at all well, 4 of the radiators are fan assisted and getting sufficient flow through them is proving problematic. My 35 year old cast iron sectional boiler worker perfectly, is this a case of modern is definately not better.
What impact might this be having on the boiler.
Is this the case that I have made my system too sophisticated for the boiler to handle.
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