The numbers on a central heating pump typically refer to its physical dimensions and pumping capacity. For example, on a pump marked 15/50/130 or 25-60:
Bear in mind that the ideal temperature for a living area is 19-20°C while for a bedroom it's 17-18°C and remember that lowering your thermostat by just 1°C will result in considerable savings.
15/50: This rating represents the pump's flow rate at a particular pressure. In this case, it signifies the flow rate at a 50-meter head. The 15/50 pump is typically used for larger heating systems. 15/60: Similar to the 15/50, the 15/60 pump indicates its flow rate, but at a 60-meter head.
130 is the length of the pump, in mm. 15 is the thread size to connect it, 15 mm being 1/2“ and I've never seen 60, normally it's 1-4, 1-6, or 1-8 which indicates the maximum height in Meter the pump can overcome.
Generally speaking with heat pumps we would aim for a DT of 5-7°c and for gas boilers a DT of 20°c, turn up the pump if the DT is too wide and down if too narrow. Many modulating boilers automatically adjust the pump speed to target dT20, these can be quickly checked, and many have settings for refinement.
In outdoor temperatures above 30 degrees, the heat pump should cycle off and on like a normal furnace. Somewhere between 20 and 30 degrees outdoor temperature, the heat pump will reach a “balance point” where the heat needed by the home is equal to the heat supplied by the heat pump. So now it will run all the time.
Pumps generally have three speeds, low, medium and high. They are adjusted by moving a dial, switch or pressing a button. If there is no option to adjust the speed of your central heating pump, then it's likely a single-speed model.
For example, if the speed setting is too fast: You will be wasting a lot of electricity and driving up bills (central heating pumps can account for 10% to 15% of your electricity consumption) The pump will generate a lot of unnecessary noise. The water will return to the boiler too warm.
Answer: The pump curve of a heating pump displays the feed rate on the x-axis and the delivery head on the y-axis. The pump curve shown in the graph is curved, dropping off from left to right.
25-80 indicates the pump's size and performance: 25 refers to the pipe connection diameter in millimeters (1 inch). 80 refers to the pump's maximum head (pressure it can generate) in decimeters, meaning it can pump water up to a height of 8 meters.
It takes time for your home to warm up and cool down. If you're not sure how long it takes, try turning the heating on about 30 minutes before you need it. You should turn it off 30 minutes before you'll stop needing it.
An oversized circulator will result in higher initial cost for the pump, greater energy use, and possible premature pipe failures due to wear and tear from too much flow, resulting in costly damages from a leaking system.
The main thing to get right is your room thermostat. Generally, you'll want to set this somewhere between 18°C and 21°C, and this will make sure the heating doesn't come on until you need it to. It also makes sure you're not overheating your home over the winter.
For the most efficient winter operation, set your thermostat to a steady 68°F (20°C) while you are home. Unlike traditional furnaces, heat pumps work best when left alone rather than constantly adjusted. Avoid large temperature "setbacks" (lowering the temp drastically), as this forces the system to work harder to reheat the home.
If your heat pump is unexpectedly expensive to run, the most common culprits are inefficient auxiliary/backup heat, high local electricity rates, or a system that isn't sized properly.
“You should only ever have your heat pump running if you're at home. Heat pumps work rapidly once you turn them on, so don't bother leaving them on when you're not there,” says James le Page, product test team leader, writing in a Consumer NZ guide.
Quick summary of the Grundfos Alpha1 25-60/130
The maximum height to which water can be pumped by the pump. This is equivalent to the pressure with which the pump handles the water (10 meters = 1 bar).
What is the difference between the two pumps? The 15-60 seems to be more efficient (B rated) and a little bit of a faster flow rate yet is cheaper, but they both appear to be for systems up to 35kw (they both have the same installation manual).
Pump Size Number
Note that the size number 1-1/2 x 3 – 6 indicates that the pump has a 1-1/2 inch discharge port, a 3 inch suction port, and a maximum nominal impeller size of 6 inches. This type of nomenclature is common, with some companies putting the 3 in the first position instead of the 1-1/2.
For most of the year, a heat pump will keep your home warm and comfortable and its carbon footprint low, but when you need an immediate boost of heat or lots of hot water at once – a backup boiler picks up the slack.
Your house is getting warmer
When your heat pump is on, then your house should be warming up (or cooling down in summer.) If that isn't happening, then there's a problem with your system's ability to transfer heat from one place to another, and it's time to call in a professional.
Most homes work well on setting II (medium). Test by feeling radiators and adjust accordingly. The goal is the lowest setting that still heats all radiators properly. Modern pumps adjust automatically based on heating demand.
A heat pump typically runs in cycles of 10 to 20 minutes, 2 to 3 times per hour to maintain a steady temperature. Under normal conditions, it averages about 6 to 8 hours of total runtime per day.
Key takeaways. Heat pumps typically last for about 15-20 years. More modern systems with proper upkeep can last even longer. Quality of installation, regular upkeep, the model of the heat pump and its usage all impacts its lifespan.
In cold climates, the system must run longer and work harder to heat the home, which puts more stress on components and can shorten life expectancy, while in hot climates, prolonged cooling cycles can overwork the system if it struggles to release heat efficiently.