Booster pump installed successfully, but now boiler goes to overheat!

[Vitali]

Hi all, need advice as I am an amateur who wanted to improve things but made it worse. Ok, have a duplex apartment with a Baxi solo 2 gas central heating. All working ok but the gravity fed shower upstairs was slow in water pressure, and I found this cheap 0.9 Bar electric booster pump on Amazon and spent half a day installing it myself and to my surprise had no leaks and when switched on it did the job as described--- water pressure increased to have a good quality shower. I installed it on a hot water feed going from hot water tank to shower. When happy with myself I switched the boiler to heat up the water, it started as usual but in 2 min cut off and overheat light came up. First I decided to reset the PCB, so I switched it off for 10 sec. The pipe going out of the boiler was really hot, so just in case I let things cool down and came back to the boiler in 20 min. Started it, it did kick in and then again in 2 min stopped and showed overheat again. So, lads, what it is-- an airlock in the system or is that my pump restricting the water circulation and what do I do? I plan to go all the way back to where I started from disconnecting the pump as we all need a Good shower now. And I only hope it will be the same as it was before.... Thanks in advance!

 

[king of pipes]

Check the circulating pump for your central heating its could be sticking or has failed , fitting a shower pump on your hotwater supply will not casuse your boiler to overheat , your heating pump is the heart of your system it circulates heated water through your radiators and through a coil in your hotwater cylinder from your boiler it is more likely to be your problem , other causes could be a zone valve fault or a electrical problem on the controls cheers kop

 

[Chalked]

Can you post a picture of where you have instead the pump.
Your booster will not affect your boiler.unless! It's been installed on the wrong pipe.

 

[deg]

Where did you get the power to run your pump from? Have you tripped your heating controls or isolated your pump supply or something similar?

 

[Vitali]

Hi, people, thanks for replying, I listened to your advice and concerns and adressed them. Firstly, I double checked all the vents I closed to stop the water when I was fitting the booster pump. And one please closed!!!! I forgot to turn it back on, the one which was going into the bottom of the coil tank. How silly I was I thought turning it back on again. I was sure that was my problem. When I turned the boiler on, it started perfectly but in 2 min cut out, though the overheat led did not light up. In 2 min the boiler started by itself, which was great news, then cut out again in 2 min. I kind of got worried that it cuts out too fast before it was longer intervals... Then OVERHEAT AGAIN! Started touching pipes and circulation pump. The pipe going from the boiler to the pump roasten hot, same as the pump, plus I can hear it running and vibrating. But the pipe going out of the pump is barely warm, so it means that the hot water is not pushed upstairs! I unscrewed the middle of the pump while it running in case there's some air or dirt trapped inside. The water was not shooting out, just fast drops. I took out the middle bolt altogether and again nothing crazy, water not shooting out just dropping out. Took a screwdriver and slightly inserted it in the middle and could feel the rotor/impeller rotating. Switched between the 3 speeds and it behaved adequate as well as dead quiet when off. Does that sounds like a healthy pump? But why then pump is not pushing the hot water further up the pipe? Is that a strong airlock? Expansion tank got hot and full of water when the boiler went to overheat. Even worse, I disconnected the booster pump and put everything back as it was before and still, boiler starts,

works close to 2 minutes and goes to overheat mood. Completely lost...what to do next?

 

[ShaunCorbs]

Turn the pump on does it still overheat ?

 

[Vitali]

I took the power from the socket in the nearest bedroom and ran the cable to install a separate socket with a switch in the hot water tank press. That's the diagram I was using to choose the right hot pipe for the pump.

View attachment 30362

 

[Vitali]

The pump is always on when the boiler is on heating and when it cuts out to overheat the pump still runs and I can't reset the PCB until everything cools down a bit.

 

[ShaunCorbs]

Was it fine / working before you did the works

 

[Vitali]

That's the thing -- all was good.