ASHP low pressure help pls

[canalsiderenovation]

 

 

[ProDave]

Yes that is the tundish.  It should remain bone dry.  IF any water passes through it would pass on the inside, it is just there so you can see if anything is passing through.  You could try rolling up a bit of tissue or toilet paper and sliding it into the space inside.  That will show you if there is any discharge even when you are not watching it.

 

It that remains dry over a few days as you use hot water and it gets re heated, then there is nothing wrong with the white expansion vessels.

[canalsiderenovation]

9 minutes ago, ProDave said:

Yes that is the tundish.  It should remain bone dry.  IF any water passes through it would pass on the inside, it is just there so you can see if anything is passing through.  You could try rolling up a bit of tissue or toilet paper and sliding it into the space inside.  That will show you if there is any discharge even when you are not watching it.

 

It that remains dry over a few days as you use hot water and it gets re heated, then there is nothing wrong with the white expansion vessels.

Thank you

 

I will turn it on later and watch it for a bit. I will then the tissue method too.... will update soon.

[Beelbeebub]

One possibility is that - for whatever reason - the system was drained down during the servicing and air entered the pipes.

 

The plumber will repressurise but as some of that trapped air gets circulated around it will eventually find it's way to an automatic air vent, either in your pipework or in the heatpump. 

 

As that bleeds out you can get a drop in system pressure. 

 

Some systems can take quite a while to purge themselves and require a couple of top up cycles.  My own system takes ages to get rid of all the air, but that's because it's crap. 

[ProDave]

1 hour ago, Beelbeebub said:

One possibility is that - for whatever reason - the system was drained down during the servicing and air entered the pipes.

He says he topped up the glycol levels so that makes sense.

[Nickfromwales]

17 minutes ago, ProDave said:

He says he topped up the glycol levels so that makes sense.

He may have used a pump-up pressure bottle to inject, vs drain down and fill via a towel rad / other. Service guys don't like getting wet.......