[Dave Pilkingto]

I have a multi fuel heating system, the system does not get all the rads hot, the farther away the rad from the appliance the cooler they are even with a roaring fire.

I have turned the electric off to the controls, and really got the water so hot it came out of the overflow pipe, restoring the power to the controls got all the rads hot, but after a while they returned to the same problem even with a roaring fire still blazing away.

There are two pipe stats on the system, one on the flow primary circ set to 90 degrees and one on the return primary circ set to 45 degrees.

Please can you help me with this problem.

Kind regards

D.Pilkington

[hvac1000]

You have to get the water to the area before the radiators will get hot.

Make sure the system water pressure is enough to lift the water to whatever level needed. The altitude (pressure) is very important for proper system operation. Usually 12 psi is good but might have to go to 16 or so on a more story building.

Removal of all air from the system by bleeding the radiators is a must and if auto venters not installed I suggest you do so. NOTE: It does no good to try and bleed the air from a system if the system pressure to low.

Usually this does not come into play since the above two are the usual problem areas but to small a pump with not enough lift can also be a problem. Most times when a system is designed the engineer or other person doing the job will calculate the pump size, lift value,and flow so a pump problem will not exist. Also a used,damaged or improperly installed pump can also cause problems.