Hopefully 3 not too difficult questions

[grizzlybiker]

I have just replaced my Grundfos pump and it would be really helpful if anyone could help me with any of the following:

1. Should this red gate value be open or closed (er what does it do) ?


http://s630.photobucket.com/albums/uu28/headache5678_photos/?action=view&current=IMG_5777.jpg

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2. I think this pipe is an “air bleed pipe for either the CH or HW. What could the grunge stain be on the side of the pipe and how / why should I fix it?


http://s630.photobucket.com/albums/...5678_photos/?action=view&current=IMG_5781.jpg

3. When replacing the Grundfos pump, I found it very tight to get to the rearmost 50mm Pump-Gate-Vale nut. Screwfix sell some “Water Pump Pliers” which may enable me to tighten the nut further but space is very tight and I am not sure they will give me the torque / leverage to get the nut any tighter. Any suggested better tool please ?

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http://s630.photobucket.com/albums/...5678_photos/?action=view&current=IMG_5776.jpg

 

[nickso]

1. It's the bypass, leave it alone if you haven't already moved it.
2. Auto air vent and it's leaking, either close the cap on the top or get someone to replace it or do it yourself.
3. Plenty of room to get a pair of grips in there. Why have you put PTFE on the threads?

 

[grizzlybiker]

Nickso,

Thank you for your comments, much appreciated.

May I ask:

(i) the By Pass gate valve is in position but it is currently Closed. Is that correct for normal operation ?

(ii) I got conflicting advice on PTFE as to whether to use it or not. Did I do wrong ?

 

[Rob]

(i) the By Pass gate valve is in position but it is currently Closed. Is that correct for normal operation ?

If the boiler doesn't have pump over run then yes

(ii) I got conflicting advice on PTFE as to whether to use it or not. Did I do wrong ?

PTFE is for when the seal is made via threaded joint or olive compression.

The seal on your pump should be 1 1/2" rubber washers which need to only be slightly more than hand tight

 

[Whitespirit66]

Putting PTFE on threads in this situation could work against you. As said, the rubber washer inside the joint creates the seal. Padding the thread out with PTFE could mean that the nut doesn't tighten down as far as it needs to compress the washer.

However, if it is OK now, it should be OK to leave.

 

[Hugh Jaleak]

'Snail SWB14' might be a better tool than the water pump pliers, but they aint cheap!

 

[grizzlybiker]

Thanks guys for your comments. I will remove the PTFE then re-tighten the 50mm nuts to give the new internal rubber washers the best chance of a watertight seal. Without PTFE I can now see that the nuts will turn more freely so that finger-tight + a smigeon extra with the small Stillsons will be all that is required.

I spoke with Ideal / Caradon Technical help desk a few minutes ago and they confirmed that my 18-year-old Ideal 2 Mexico RS100 boiler did not have Pump Overrun and that the Bypass Gate Value should be left Open in normal operation.

The Technical Desk said that if I had turned off all radiators (I have a mix of TRVs and non-TRVs) - but left the boiler swicthed on - there is a risk that the boiler would overheat if the Bypass Gate Valve was closed. That sounds logical to me.

 

[namsag]

Also one of the most common faults on CH systems is microswitch sticking in motorised valve
and bringing boiler and pump on with no demand. Open bypass gives it somewhere to go.

Usually from closed 1 turn to open it is enough dont fully open it. It will rob your system by short circuiting it so to speak