Central heating problem

[68wayne19]

When you talk about the ‘H’ setup of pipe work is this what was done to my father in law’s pipe work? Thanks for your advice

 

[Hugh Jaleak]

Yes, although I wouldn't have put those bends in if it could have been avoided. The vent pipe needs to rise as much as possible to terminate over the F&E cistern, I'd try and make it take a less complicated route if at all possible!

 

[68wayne19]

The more I think about it the more I think it’s a blocked cold water return, especially on the return from the hot water pipe,(hardly any water flowing through the hot water tank heating element which has resulted in a limited amount of hot water in the tank although the pipe is hot going into the element) this pipe is currently connected directly to the cold water fill pipe in T piece as seen in the photo bottom left

Can I cut the 15mm cold water pipe as it comes out of the floor, blank it off (hopefully bypassing the blockage and having to have the floor up)and reconnect it to the 22mm pipe below the pump along with the re-routed vent pipe?

 

[Terrywookfit]

Have a play with a strong magnet on the pipes to locate blockages.

 

[68wayne19]

I’ve just ran a magnet over the 15mm copper pipe and right on the T piece the magnet senses metal within an inch of that joint suggesting that may be where the blockage is?

 

[Terrywookfit]

Correct!

 

[68wayne19]

T piece cut out, this area was quite blocked, replaced T piece and surrounding pipe. Heating slightly better possibly sludge further down the 15mm pipe, although this can get quite hot which would suggest hot water is coming up this pipe as apposed to coming out the bottom of the hot water tank. Vent pipe gets quite hot but quickly goes cold. Really trying to avoid having the floor up, so I’m going to let it run for a few days to see if there’s any change.

 

[68wayne19]

Central heating has been running a week since I removed the blockage I’d identified on the return from the hot water cylinder return. Since doing this, central heating is never been so good, however when the hot water side is either working on it’s own or along with the central heating occasionally hot water gets sent back up to the tank in the loft and comes out of the overflow.
As I’ve mentioned be when someone was trying to sell me a boiler which I didn’t need they mentioned that the piping in the airing cupboard was wrong but didn’t say what the problem was.
The only thing I can think is that the vent and the water feed needs to be moved to below the pump, they may already be piped this way, however without lifting the flooring I won’t be able to confirm this.
Your thoughts would be appreciated

 

[HERTS P&D]

Try turning your pump speed down.

Andy

 

[68wayne19]

What would the correct settings be for the pump fitted Grundfus ups3 ?

 

[HERTS P&D]

What would the correct settings be for the pump fitted Grundfus ups3 ?

All depends on the size and layout of your system. But by turning the pump speed down could be the easiest and quickest fix anyone could do. As long as all of the rads heat up and the hot water is working then by turning it down will also save on electric.

Andy

 

[Hugh Jaleak]

You have what we spoke about earlier in the thread, 'Pumping over'. I would recommend you alter the cold feed as shown to achieve the 'H' arrangement and create a neutral point in the system, which should hopefully eradicate the issue.

 

[68wayne19]

So basically move the 22mm vent pipe and 15mm cold water pipe to the 22mm pipe below the pump?

 

[Hugh Jaleak]

Sorry, its a bit more complicated than that, I wasn't looking at the picture properly in the first place earlier. (Joys of a 2 year old who's just found the hammer I'd forgotten was in the living room windowsill....) In your situation the Pump would need moving I think, as you need to create a similar arrangement to that in the picture you posted earlier of your Father in Law's system.

The Flow pipe from the boiler needs to rise continuously with no restrictions to a suitable point over the F&E Cistern. (Have to wonder if that's really a safe setup you have currently if the pump is in the run between the boiler and open vent...) Then at a suitable/convenient point, Tee off, and couple the cold feed in within 150mm of the vent, to create your Neutral point. From there run to the pump, then back down to your 3 port valve.

If there is room to rotate the 3 port valve by 90° then the job should be relatively straightforward. Remove pump, connect pipes across former pump position. Further up, cut in a Tee, go to the right slightly, connect cold feed, then turn down 90°. Fit pump here, then run down to 3 port Valve, turning towards cylinder 90° to enter valve. Cap off former cold feed as close to point of connection as possible.

 

[68wayne19]

Looks like I’m going to have to get a plumber in on this one.