Vent problems after tank move

[Andy mcgill]

Hello everyone, this is my first post.
I am having problems with my upstairs hot water taps first thing in the morning.
The system is an open vent with a cold storage tank in the loft and a direct hot cylinder on the first floor.
The problem started about 5 years ago when I extended my bathroom and fitted a gravity feed power shower. First thing in the morning when you switched the shower to eco, the pump would race for 30 seconds as if it was drawing air. This was not really a problem until the last day when I decided to move the hot cylinder to the front porch to free up the sitting room cupboard,which would allow me to take down the wall. The move added about 4 meters of pipe on the cold feed and the same on the hot take off.
After the move the shower has no water at it and I have to run the bath tap and sink tap to bleed out the air.This gets water to the shower.
So I have just examined the system and I think the air is being trapped when the tank is heated during the night.
The vent pipe is wrong I think,because the hot 22 mm pipe comes off the top of the tank goes up to the toilet and then up to the cold tank to vent.The hot taps are tee,ed off in the bathroom and not at the tank.
I don't want to totally repipe the vent so thought about installing an air vent valve on the hot leg as it leaves the tank.
Don't know if all this makes sense but I would like your thoughts.
Thanks

 

[rpm]

Seperate pump feeding water to the shower and did you move the pump as well?

 

[Andy mcgill]

Seperate pump feeding water to the shower and did you move the pump as well?

No mate pressure comes from head of cold tank.Shower has a pump on it.

 

[king of pipes]

Sounds like it is piped wrong you should have independent supplies for the shower pump feeds as attached . Kop

 

[rpm]

Don`t disagree there is something wrong bud, however unless I`m wrong it is a box on the wall, no seperate pump this time.

 

[king of pipes]

Aquastream type shower ? It Will still need a Essex type flange for the hot feed and separate cold from CWS tank. Not shared . Kop

 

[Andy mcgill]

Aquastream type shower ? It Will still need a Essex type flange for the hot feed and separate cold from CWS tank. Not shared . Kop

The shower is a Newteam.The problem is worse this morning.Low flow on the hot taps until you switch the shower on to bleed the system.Think I will order an air vent and try it on top of the cylinder

 

[ChippyCal]

Bleed the system, install vent, and renew / clean pump.

 

[Aire]

What's the distance between the top of the shower and the bottom of the cold water storage tank in the loft?

 

[Riley]

You dont need an air vent you most likely need the correct flange as mentioned before

 

[Aire]

OP, can you take photos of the installation, a pic of the cylinder and where you have taken you hot supply from and a pic of your cold water supply too please.

 

[ChippyCal]

The vent pipe is wrong I think,because the hot 22 mm pipe comes off the top of the tank goes up to the toilet and then up to the cold tank to vent.The hot taps are tee,ed off in the bathroom and not at the tank.
I don't want to totally repipe the vent so thought about installing an air vent valve on the hot leg as it leaves the tank.
Don't know if all this makes sense but I would like your thoughts.
Thanks

Just a thought reading this, is HOT and COLD connected the right way around?

 

[Andy mcgill]

What's the distance between the top of the shower and the bottom of the cold water storage tank in the loft?

View attachment 37195

Distance is 1.2 meters

 

[Andy mcgill]

Just a thought reading this, is HOT and COLD connected the right way around?

Hot and cold are definitely correct.

 

[Andy mcgill]

You dont need an air vent you most likely need the correct flange as mentioned before

What is the correct flange bearing in Mind-this installation was done in 1984 and all I have changed over the years is the fitting of the shower and moving of the tank a few days ago

 

[Riley]

Give us some pics and we’ll check

 

[Andy mcgill]

Give us some pics and we’ll check

Pics of cylinder and shower

 

[ShaunCorbs]

Where’s the vent as atm the cylinder isn’t vented

 

[Andy mcgill]

Where’s the vent as atm the cylinder isn’t vented

That's the point.The hot water pipe exits the cylinder and goes up to the cold tank where it hangs over the edge of the tank. The hot taps are tee,d off this pipe. Can I put an air valve in the short pipe exiting the tank?

 

[ChippyCal]

=

 

[Best]

Who did that work!!!!
Pipe from top of cylinder always needs a vent of it.
That has no chance of working

 

[Aire]

You need to tee off here and vent this pipe into the cold tank in the loft

 

[ShaunCorbs]

That's the point the hot water pipe exits the cylinder and goes up to the cold tank where it hangs over the edge of the tank. The hot taps are tee,d off this pipe. Can I put an air valve in the short pipe exiting the tank?

Wrong think you should get the person back who did the work

 

[Riley]

Totally agree. Verging on being dangerous

 

[Harvest Fields]

Needs sorting and to me would be a priority. Get them back ASAP.

 

[Riley]

In addition I’m not sure plastic is the most sensible straight off the cylinder. Someone really needs a word in your installers ear

 

[Andy mcgill]

In addition I’m not sure plastic is the most sensible straight off the cylinder. Someone really needs a word in your installers ear

That's the point I am trying to make. This is the way all these houses in this estate were installed in 1984.To run in entirely new pipe would be a nightmare as the pipes go from under the house up through stud walls through floor joists and behind stud walls.
I do know this is not right but it is what I am left with,but will putting an auto vent valve in the plastic pipe leaving the tank work or not.

 

[Riley]

No do you understand what the vent is for

 

[Riley]

The fact that you have moved the cylinder doesn’t negate the fact that it still needs to be correctly plumbed to G3 regs

 

[Riley]

Also good swerve on the issue with the plastic

 

[Andy mcgill]

Also good swerve on the issue with the plastic

All my house has been done in plastic.
Are you telling me this is not fit for purpose.

 

[Riley]

They can’t deal with the temp should your cylinder overheat likewise your vent pipe needs to be correctly reinstalled in copper. Who re-pipes it all in plastic?

 

[Riley]

Please stop ignoring the vent issue too we are thinking of your safety here. If you have moved the cylinder yourself then you really really needed to have a clue on what the pipes actually do. The vent pipe is not just for getting air out of the system and needs to be correctly plumbed to cope with any safety failures.

 

[Andy mcgill]

They can’t deal with the temp should your cylinder overheat likewise your vent pipe needs to be correctly reinstalled in copper. Who re-pipes it all in plastic?

Tank is fitted with a 6 bolt howden which has one control thermostat and an over-temperature safety thromostat for protection,this complies with the current IEE REGULATIONS TO BS7671.If you had read the post correctly the pipe runs up to the cold tank which means if both stats fail and the tank over heats the superheated water will flow into the cold tank in the loft.THE HOT WATER IS TEE,D OFF THIS VERTICAL dare l say it VENT pipe.

 

[ShaunCorbs]