heating problem

stehayes

Hey folks I have a vokera mynute 16e and the expansion vessel located at the back of the boiler is letting water out when I press on the air pump. Is it knackered?

There is also an expansion vessel in the hotpress and no water comes out when I check the air inlet. Is it normal to have two expansion vessels? The pressure in the system keeps rising to 2 bar and back and keeps knocking off every few minutes.

Your help would be very much appreciated. Ste

sullzz

stehayes wrote: »

Hey folks I have a vokera mynute 16e and the expansion vessel located at the back of the boiler is letting water out when I press on the air pump. Is it knackered?

There is also an expansion vessel in the hotpress and no water comes out when I check the air inlet. Is it normal to have two expansion vessels? The pressure in the system keeps rising to 2 bar and back and keeps knocking off every few minutes.

Your help would be very much appreciated. Ste

You probably have a 2nd vessel in your hotpress as the one at your boiler was found to be faulty and as a cheaper option replacement vessels are sometimes relocated to hot presses , it is correct for no water to come out of a vessel when pressing the schrader valve , but what you have now done is let air out of the vessel which is going to have to be replaced , why are you at the vessels anyway , you are going to need a plumber / rgi in to check the vessel and recharge it to its correct pressure , in relation to your boiler issue get the rgi to check that when he is there

stehayes

Thanks for your help I was just double checking I'm a plumber myself the heating isn't my strongest side and ive been out of the game for a bit so just needed a second opinion. No air came out of the exp vessel in the hotpress would you wreckon I pump air in? Or just replace vessel?

sullzz

stehayes wrote: »

Thanks for your help I was just double checking I'm a plumber myself the heating isn't my strongest side and ive been out of the game for a bit so just needed a second opinion. No air came out of the exp vessel in the hotpress would you wreckon I pump air in? Or just replace vessel?

I'd try pumping air back in (about 1 - 1.5 bar) before replacing it although a new vessel is cheap and wouldn't be too much involved in replacing it as its in the hotpress . With regards to the boiler , are you getting any circulation

stehayes

It's circulating and all rads are heating fine but as I said it constantly cuts out and then cuts back in a few minutes later. It was my plan to get a new expansion vessel for the hotpress but is it ok to leave the vessel in the boiler as is or should I change that too?

sullzz

stehayes wrote: »

It's circulating and all rads are heating fine but as I said it constantly cuts out and then cuts back in a few minutes later. It was my plan to get a new expansion vessel for the hotpress but is it ok to leave the vessel in the boiler as is or should I change that too?

It costs an arm and a leg for a vessel for the boiler itself , if its not leaking leave it alone or you could drain it and blank off the supply pipe to it

stehayes

Thats great thanks a mil for your help mate really appreciate it

JohnnieK

If it's heating everything and cutting in and out it sounds like it's working fine. There is probably no temperature controls on the system and the boiler is operating on it's own stat.

stehayes

I think your right I put in a new expansion vessel today and the pressure is fine but it still keeps knocking off and on every few minutes obviously reaching temperature. Any ideas to keep it running and is it bad for the system if it keeps knocking on and off?

shane0007

stehayes wrote: »

The pressure in the system keeps rising to 2 bar and back and keeps knocking off every few minutes.

When you say if goes to 2 bar and back again, what is going back to and how often?

If happening all the time, it sounds like a blocked heat exchanger.

stehayes

It reaches 2bar and then when it's off for a while it drops to about 1.5 bar but even when I release the pressure to say 0.5 bar and fire up again it gradually makes its way back up to 2bar over the day. It's constantly reaching temp and cutting out. Also I noticed the hot water is too hot would this be related?

jimjimt

You should have 1 bar of pressure in your vokera vessel and 1 bar in your secondary vessel.

You can only pump air and test your vessel with there is no pressure in the system and even then if you can disconnect the vessel and pump to 1 bar would be better.

The pressure on your heating system should then be 1 bar cold.

If you are getting up to 2 to 2.5 bar you will put pressure on your vokera heat exchanger which is not good and will damage it.

shane0007

stehayes wrote: »

It reaches 2bar and then when it's off for a while it drops to about 1.5 bar but even when I release the pressure to say 0.5 bar and fire up again it gradually makes its way back up to 2bar over the day. It's constantly reaching temp and cutting out. Also I noticed the hot water is too hot would this be related?

Only adjust the system pressure when the system is cold. 2 bar pressure when hot is acceptable. Let the system go cold and check pressure is at between 1.0 & 1.5 bar. I usually set to 1.2 bar. See if the pressure remains at about 1.8 when hot.
You can only check the vessel pressure when there is no water pressure against it.