Ariston Unvented Heater - installation problem

[spaceangel]

Hello

My husband has fitted a 2KW, 10L Ariston unvented under counter water heater. It all looks fine, he has followed an online tutorial. However, there is no water coming out of the hot water tap at all. He is baffled as to why? There is plenty coming out of the cold tap though.

Any advice would be appreciated.

Thanks in advance.

 

[SimonJohns]

Any photos?

Sounds like a valve has been installed the wrong way around

 

[spaceangel]

I can get some photos for you tomorrow. Which value could it be? It came with a pressure relief valve. Could it be that his has been installed incorrectly?

 

[Barry98]

Does he have the relevant qualifications to fit this ?

 

[SimonG]

Should have had a check valve, which ways the arrow pointing on it.

 

[Barry98]

This is on page one of the book that will of come with it


Building Regulations
These are a statutory document and take priority over all other regulations and recommendations. The installation of an unvented hot water system of over 15 litres is classified as a “Controlled Service” and Regulation G3 applies. To meet the requirements of the regulation, installation of an unvented system should be undertaken by a “competent installer”.
All installations of unvented hot water storage systems having a capacity of more than 15 litres should be notified to the relevant Local Authority by means of building notice or by the submission of full plans. It is important to note that it is a criminal offense to install an unvented hot water storage system over 15 litres without notifying the Local Authority.

 

[spaceangel]

Should have had a check valve, which ways the arrow pointing on it.

Away from the actual heating unit.

 

[Barry98]

Apologises you've said 10 litre

 

[spaceangel]

This is on page one of the book that will of come with it


Building Regulations
These are a statutory document and take priority over all other regulations and recommendations. The installation of an unvented hot water system of over 15 litres is classified as a “Controlled Service” and Regulation G3 applies. To meet the requirements of the regulation, installation of an unvented system should be undertaken by a “competent installer”.
All installations of unvented hot water storage systems having a capacity of more than 15 litres should be notified to the relevant Local Authority by means of building notice or by the submission of full plans. It is important to note that it is a criminal offense to install an unvented hot water storage system over 15 litres without notifying the Local Authority.

Thank you. The unit is only 10 litres. Also, he has basic plumbing from many years ago. He's just not fitted anything like this before.

 

[SimonG]

Away from the actual heating unit.

Should be pointing to it, on the cold supply to the unit.

 

[spaceangel]

Too add, he said that he has two isolation valves on the flexi pipes leading from the taps to the copper piping which the leads to the unit. Not sure if that has any relevance?

 

[spaceangel]

Should be pointing to it, on the cold supply to the unit.

Is that with both hot and cold? Or just the cold?

 

[Skelly87]

The check valve should only be on the cold supply to the heater and before the expansion vessel and pressure relief valve

 

[spaceangel]

The check valve should only be on the cold supply to the heater and before the expansion vessel and pressure relief valve

Thank you. We don't have an expansion vessel on our unit, but I will tell him what you have said.

 

[Barry98]

some pics would still help

 

[spaceangel]

some pics would still help

I will take some when we go over to the shop tonight. We are opening a cafe, so need a hot water supply, hence the installation.

 

[Barry98]

No problem space angel

thanks

 

[lbp plg & htg]

Is it to supply standard taps or has he fitted a mixer tap?

 

[spaceangel]

All sorted. The valve wasn't on! Two second job and we now have plenty of hot water.

Thank you to everyone for your help, it was much appreciated.

 

[Deleted member 25704]

Thank you. We don't have an expansion vessel on our unit, but I will tell him what you have said.

If you read the installation instructions it may state that for cold water supplies in excess of 4 bar, the expansion vessel kit should be fitted. In my experience most mains supplies are over 4 bar, so the expansion vessel kit is nearly always necessary.

The fact that you have fitted a check valve on the cold supply, means that the expansion from the hot water will be accomodated through the 'pressure relief valve' which means it will drip occasionally, when the heater warms up. If you are on a water meter this will be an expensive drip, as the valve itself will soon become corroded and will not re-seat, resulting in a constant drip, which wastes water and energy.

 

[Skelly87]

Like bod says pictures would be usefull. There is a way the heater can be installed without an expansion vessel by using a certain length of pipework to take up the expansion. You need to make sure this unit is installed CORRECTLY, if the pressure relief valve has been fitted incorrectly then you have a potential for a small explosion. Even if the heater going pop doesnt cause much damage, then the damage from the water will be high if it pops whilst your out