Grundfos Pump Direction

[craxj]

Hi all. My boiler kept cutting off last week and had an Engineer round to get it fixed. I have an open vent system with a small tank in the loft which feed water to system and there is also a vent going up in the loft. The problem was blocked T section above the pump which was carrying a small horizontal pipe connecting vent pipe and cold feed pipe above pump
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My question is I had a new Grundfos 15/60 pump installed 4yrs ago. It has isolation valves on both sides. Previously the pump was installed and remained in such position for 4 years that it would appear upside down with writing on the front upside down, cable coming out from top and speed control lever accessible from front. The arrow next to front bleed screw in anti-clockwise direction but the arrow on the side of pump facing upwards towards loft and installed on the cold feed pipe. The cold feed pipe and vent are also connected with a small horizontal pipe above the pump and there is also a small copper drum housing at this horizontal joint at vent pipe. Below the pump the pipe leads to the hot water tank and also to the Honeywell Mid Pos Valve.

Now since the Engineer has carried out repair he has turned the pump other way around (I am thinking it was working fine for 4 yrs then that must be the right flow direction or may be not). It seems now that writing is right way round, arrow at the front near screw is still anticlockwise but arrow on the side of pump body now facing downwards i.e in line with pipes going towards hot water tank and Mid Pos valve. Cable now coming out from bottom of pump and speed lever on the back side. All this is located in airing cupboard. The boiler is located downstairs in the kitchen (Ideal Classic FF270). Does this change in pump direction make any difference? It seems very slightly noisier than before and one of the downstairs radiator slightly less warmer than before. Otherwise all seems to be working.

If somebody can answer that would be great.

Thanks

 

[DP]

The vent and feed (if these are close together) MUST be between the pump and the boiler flow (hot out ) connection. The pump will then be fitted with arrow on the body pointing flow of water away from the boiler. Ignore arrow on the motor itself.

 

[craxj]

DP that means the previous installation with arrow on the body pointing upwards with pump seems inverted was right. The boiler is in the kitchen. then I have water tank, mid pos valve and pump in the airing cupboard. the cold feed and vent are connected in the airing cupboard above the pump and then both pipes go into the loft. I am more inclined to change the arrow direction upwards as it was working fine for 4 yrs. What affect will it have if it isn't in right direction and arrow is pointing downwards i.e towards boiler and mid pos valve. Sorry I didnt get your answer completely so I have tried to explain a bit more.

Another question, how can I check which pipe is return and which pipe is flow

 

[45yearsagasman]

View media item 32248Ignore the fact that this is S plan, the pipes must be as shown and the arrow on the pump body MUST point to the valves etc(in your case a mid pos valve) and no other orientation is correct.

 

[craxj]

Pete,

Thanks for resonse. I dont understand the full diagram but yes setting in my house seems in accordance with the diagram upto valves (yes I have a mid pos valve instead of 2 separate valves as shown in diagram). Pump arrows is pointing downwards towards mid pos valve now so I should be safe. Just confused why the previous plumber installed with arrow pointing away from valve, and I had no disaster in 4yrs.

 

[ianmcd]

Pete,

Thanks for resonse. I dont understand the full diagram but yes setting in my house seems in accordance with the diagram upto valves (yes I have a mid pos valve instead of 2 separate valves as shown in diagram). Pump arrows is pointing downwards towards mid pos valve now so I should be safe. Just confused why the previous plumber installed with arrow pointing away from valve, and I had no disaster in 4yrs.

If the pump was fitted the wrong way you wouldnt have a disaster it just either wouldnt work or wouldnt work efficiently sometimes the worst symptom is just noise if the pump is fitted wrongly sometimes causes OH stat if fitted on boiler to cut out

 

[craxj]

Further to above problem, it lasted 2 weeks and this morning we woke up and turned the heating on to realise the boiler is not firing up at all. Pump is running. Left it all fine last night. Could it be another block and shall I get it power flushed as the plumber had suggested when he carried out repir. Freezing