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Frequently asked questions
Multifuel boilers | Solar | Wood boilers | Thermal storage | Domestic hot water
MULTIFUEL BOILERS
Q - Does the oil / gas turn off automatically if I'm using the log side of the boiler ?
A - Yes, the boiler's oil / gas burner is controlled by an adjustable thermostat. This thermostat is immersed into the water tank
inside the boiler and as soon as the log side of the boiler starts producing heat, the oil / gas burner will switch off.
Q - How does the oil / gas burner switch back on ?
A - It is a reverse of the above. When the logs are burned out, the water temperature inside the boiler starts cooling slowly.
The cooling is faster when the heating or domestic hot water are used.
As soon as the boiler cools down below the set temperature on the burner thermostat, the oil / gas burner starts automatically.
Q - How do I connect a wind turbine, solar photovoltaic panels or a water turbine to the boiler ?
A - All our multifuel boilers are fitted with an electric immersion heater. This heater is designed to also accept 3-phase connection and
has three separate elements, 2kW each. These elements can all run from a single source of power, or they can be used singly.
This allows a simultaneous connection to three separate electricity sources. Our download page has an electrical drawing for this element.
Q - How do I connect solar thermal panels to the boiler ?
A - Jaspi multifuel boilers can be fitted with a dedicated solar coil. This coil is used to connect to the solar thermal panels. The advantage of doing this instead of connecting to a separate solar cylinder is that the heat from the solar panels can then be used for both, heating and hot water.
This accumulated heat will also reduce the running hours of the oil / gas burner and will reduce the need to use the wood burner.
In fact, it is common that the solar will produce all the heat needed either to heating or hot water from April to October.
Q - What are the recommended solar panel sizes for the boilers ?
A - DUO 1 with 160L water capacity - 2.5sqm, Duo 2 with 240L water capacity - 4sqm.
Q - Do I still need a domestic hot water cylinder or a thermal storage tank ?
A - You do not need a separate hot water cylinder with our multifuel boilers. All our boilers have a built-in domestic hot water coil which heats up the hot water as you use it. It is also rated to a mains pressure of 10bar.
A thermal tank is not necessary either, however, if you intend to use logs as your main heat source, a thermal tank will help to retain a larger amount of produced heat which in turn reduces the frequency of lighting up the wood boiler.
Q - How do I connect the boiler to the radiators ?
A - All our multifuel boilers come with a heating mixing valve. This valve has to connections; flow & return. A circulation pump is fitted to the pipework after this valve, to the flow pipe. The mixing valve is manually adjusted to mix a certain amount of hot water from the boiler to the return from the heating system.
To make this mixing more accurate, we recommend to install a heating controller onto the valve. The motorized controller will adjust the valve according to the heating circuit's need and will preserve the heat within the boiler. This in turn reduces the boiler running hours and saves energy.
Suitable heating controllers are from Automix range, for example CT constant temperature controller, Automix 10 weather compensated controller or Automix 30 weather compensated and time adjusted controller. More information can be found from; www.termomix.co.uk/heating_controllers.html
SOLAR THERMAL
Q - How are the solar panels connected to your thermal tanks or boilers ?
A - Via an indirect coil. The solar thermal is an independent, closed circuit that runs on a mixture of solar transfer liquid and water.
This liquid cannot be in contact with your radiator water or domestic hot water.
Q - What size of solar panels do I need ?
A - The solar panels or tubes must be chosen to match your thermal store or boiler water capacity. Too many panels v. the water
capacity will overheat the system quickly leading to other problems. Too few panels do not harm the system in any way but will
reduce the efficiency.
As a rule of a thumb, the panel size should be calculated on the maximum output in the summer, not in the winter.
The recommended solar panel size vary between the panel manufacturers so it is very difficult to give exact figures but as an example,
we have been fitting 4sqm flat panels with our multifuel boilers (240L water capacity), 4-6sqm with Oval 1.2 thermal tank and 7-9sqm with Oval 1.8 tank.
Q - The plumber have fitted a solar hot water cylinder (not Jaspi) into our house but the cylinder overheats frequently when the solar panels are working. What should we do ?
A - The obvious solution is to fit a larger cylinder or a thermal tank. An effective solar thermal store is large, 500 L and up, it is often
unpractical to try to fit this tank to the same space where the smaller cylinder is, so the larger tank is often located elsewhere like in the garage.
In these installations we often use Termomat heat transfer controllers from Automix, www.termomix.co.uk.
Q - Does the oil / gas turn off automatically if I'm using the log side of the boiler ?
A - Yes, the boiler's oil / gas burner is controlled by an adjustable thermostat. This thermostat is immersed into the water tank
inside the boiler and as soon as the log side of the boiler starts producing heat, the oil / gas burner will switch off.
Q - How does the oil / gas burner switch back on ?
A - It is a reverse of the above. When the logs are burned out, the water temperature inside the boiler starts cooling slowly.
The cooling is faster when the heating or domestic hot water are used.
As soon as the boiler cools down below the set temperature on the burner thermostat, the oil / gas burner starts automatically.
Q - How do I connect a wind turbine, solar photovoltaic panels or a water turbine to the boiler ?
A - All our multifuel boilers are fitted with an electric immersion heater. This heater is designed to also accept 3-phase connection and
has three separate elements, 2kW each. These elements can all run from a single source of power, or they can be used singly.
This allows a simultaneous connection to three separate electricity sources. Our download page has an electrical drawing for this element.
Q - How do I connect solar thermal panels to the boiler ?
A - Jaspi multifuel boilers can be fitted with a dedicated solar coil. This coil is used to connect to the solar thermal panels. The advantage of doing this instead of connecting to a separate solar cylinder is that the heat from the solar panels can then be used for both, heating and hot water.
This accumulated heat will also reduce the running hours of the oil / gas burner and will reduce the need to use the wood burner.
In fact, it is common that the solar will produce all the heat needed either to heating or hot water from April to October.
Q - What are the recommended solar panel sizes for the boilers ?
A - DUO 1 with 160L water capacity - 2.5sqm, Duo 2 with 240L water capacity - 4sqm.
Q - Do I still need a domestic hot water cylinder or a thermal storage tank ?
A - You do not need a separate hot water cylinder with our multifuel boilers. All our boilers have a built-in domestic hot water coil which heats up the hot water as you use it. It is also rated to a mains pressure of 10bar.
A thermal tank is not necessary either, however, if you intend to use logs as your main heat source, a thermal tank will help to retain a larger amount of produced heat which in turn reduces the frequency of lighting up the wood boiler.
Q - How do I connect the boiler to the radiators ?
A - All our multifuel boilers come with a heating mixing valve. This valve has to connections; flow & return. A circulation pump is fitted to the pipework after this valve, to the flow pipe. The mixing valve is manually adjusted to mix a certain amount of hot water from the boiler to the return from the heating system.
To make this mixing more accurate, we recommend to install a heating controller onto the valve. The motorized controller will adjust the valve according to the heating circuit's need and will preserve the heat within the boiler. This in turn reduces the boiler running hours and saves energy.
Suitable heating controllers are from Automix range, for example CT constant temperature controller, Automix 10 weather compensated controller or Automix 30 weather compensated and time adjusted controller. More information can be found from; www.termomix.co.uk/heating_controllers.html
SOLAR THERMAL
Q - How are the solar panels connected to your thermal tanks or boilers ?
A - Via an indirect coil. The solar thermal is an independent, closed circuit that runs on a mixture of solar transfer liquid and water.
This liquid cannot be in contact with your radiator water or domestic hot water.
Q - What size of solar panels do I need ?
A - The solar panels or tubes must be chosen to match your thermal store or boiler water capacity. Too many panels v. the water
capacity will overheat the system quickly leading to other problems. Too few panels do not harm the system in any way but will
reduce the efficiency.
As a rule of a thumb, the panel size should be calculated on the maximum output in the summer, not in the winter.
The recommended solar panel size vary between the panel manufacturers so it is very difficult to give exact figures but as an example,
we have been fitting 4sqm flat panels with our multifuel boilers (240L water capacity), 4-6sqm with Oval 1.2 thermal tank and 7-9sqm with Oval 1.8 tank.
Q - The plumber have fitted a solar hot water cylinder (not Jaspi) into our house but the cylinder overheats frequently when the solar panels are working. What should we do ?
A - The obvious solution is to fit a larger cylinder or a thermal tank. An effective solar thermal store is large, 500 L and up, it is often
unpractical to try to fit this tank to the same space where the smaller cylinder is, so the larger tank is often located elsewhere like in the garage.
In these installations we often use Termomat heat transfer controllers from Automix, www.termomix.co.uk.