Cycling Boiler

I have a systemate III and teh boiler keeps cycling even thougth the temp on the store seems to be hot enough. It cycles on for a few seconds. Goes off then about 30 seconds later will cycle again this happens a lot.

The readings from the lcd are

On - off - store - phe - dhw if that is correct i have taken these readings when its cycling

66 - 69 - 68 - 60 - 64
67 - 70 - 65 - 61 - 64
67 - 70 - 71 - 62 - 66
68 - 71 - 70 - 60 - 65
65 - 68 - 70 - 63 - 66

Could this be to do with the pump not circulating the water.

James

Hi Jaycee,

Yes if the boiler is firing for such a short time this indicates low water flow rate through the boiler. This could be the pump not running. Could be jammed or it could be a control board logic error/failure.

Cheers, Mike

Do you mean pump circuit board or systemate iii board ?

The Pump seems to be running at same speed whichever setting it is on 1 2 or 3 so looks like pump issue.

I meant the control board in the III.

The pump running at the same speed whatever the speed setting suggests something else though. The pump has no water in it! The 'no load speed' on a pump is approximately the same whatever the speed setting. Once filled with water and purged of air the speed will vary when the speed setting is changed.

Cheers, Mike