Hi all, hoping someone can help me!
I've got an Atag IR24 system (heat only) boiler installed a couple of years ago and I'm having a problem with it short cycling. I'll try to describe my heating system as best as possible: it comprises of 13 radiators of various sizes most of which have trvs turned up to max, with 4 upstairs ones about halfway. Heating flow and return circuits are 22mm pushfit with 10mm legs to all radiators. Hot water is a 170l megaflo cylinder. Central heating and hot water are controlled separately by their respective thermostats and a programmable thermostat which we currently have set on all day for both hot water and heating as we're at home all the time. There is a header tank in the attic with just one feed into the main pipe to top the system up incase any water is lost. There is no expansion pipe into the header tank so I believe this makes my system an unvented system (am I correct??) I've tried to do a bit of diagnosis; all thermostats and programmer seem to work correctly, automatic gate valves are not stuck and both open and close correctly according to demand. Pump seems to run fine and is set to maximum speed. I'll include a pic below of the plumbing near the megaflo where all the valves and pump are located. Problem we're having is even though the central heating stat is set to 30⁰c the atag boiler is short cycling and the house isn't getting warmer than about 18⁰c, we want about 21-22⁰c. This may have been happening for a long time but its only noticeable now when it's much colder outside. Worth noting the boiler does not have an external temp sensor.
Boiler settings are as follows:
Water temperature is set to 80⁰c by original installers. I've taken some data from the boiler when it's been short cycling. Picture shows what the codes correspond to. When it runs for about 5 mins and then cuts off: A0 is around 84, A1 is around 55, and A3 is around 80. So the return temp is not anywhere near the flow temp or the desired 80⁰c. It also sometimes runs for as little as 1 minute, so A0 is around 80, A1 is around 50, A3 is around 75. The strangest thing about this is it sometimes works completely normally, running for 15 ish minutes at a time and the A0 and A3 values are very similar although A1 is usually a bit below.
Anyone have any idea what's going on?? Also should the flow (A0) and return (A1) values be similar at the point the boiler cuts out? Sorry for the long post and thanks I advance for any replies
I've got an Atag IR24 system (heat only) boiler installed a couple of years ago and I'm having a problem with it short cycling. I'll try to describe my heating system as best as possible: it comprises of 13 radiators of various sizes most of which have trvs turned up to max, with 4 upstairs ones about halfway. Heating flow and return circuits are 22mm pushfit with 10mm legs to all radiators. Hot water is a 170l megaflo cylinder. Central heating and hot water are controlled separately by their respective thermostats and a programmable thermostat which we currently have set on all day for both hot water and heating as we're at home all the time. There is a header tank in the attic with just one feed into the main pipe to top the system up incase any water is lost. There is no expansion pipe into the header tank so I believe this makes my system an unvented system (am I correct??) I've tried to do a bit of diagnosis; all thermostats and programmer seem to work correctly, automatic gate valves are not stuck and both open and close correctly according to demand. Pump seems to run fine and is set to maximum speed. I'll include a pic below of the plumbing near the megaflo where all the valves and pump are located. Problem we're having is even though the central heating stat is set to 30⁰c the atag boiler is short cycling and the house isn't getting warmer than about 18⁰c, we want about 21-22⁰c. This may have been happening for a long time but its only noticeable now when it's much colder outside. Worth noting the boiler does not have an external temp sensor.
Boiler settings are as follows:
Water temperature is set to 80⁰c by original installers. I've taken some data from the boiler when it's been short cycling. Picture shows what the codes correspond to. When it runs for about 5 mins and then cuts off: A0 is around 84, A1 is around 55, and A3 is around 80. So the return temp is not anywhere near the flow temp or the desired 80⁰c. It also sometimes runs for as little as 1 minute, so A0 is around 80, A1 is around 50, A3 is around 75. The strangest thing about this is it sometimes works completely normally, running for 15 ish minutes at a time and the A0 and A3 values are very similar although A1 is usually a bit below.
Anyone have any idea what's going on?? Also should the flow (A0) and return (A1) values be similar at the point the boiler cuts out? Sorry for the long post and thanks I advance for any replies