New Central heating but problems, Please help

[Dale Sanders]

If I get 13lpm then I'll be happy. At the moment I'm getting 9-10lpm.

 

[Last Plumber]

A 36 KW Combi, 240 litre vessel and £5670, to give you 13 lpm seems absurd.

Is this a DIY gone wrong ?

Sorry Dale but if it isn’t, you need to be asking for this to be put right without any further expense to yourself !

Surely the installer took measurements of pressure and flow amongst other things before doing the job ?

 

[Stigster]

But I am sure that Dale Sanders is on about pitting the accumulator onto there existing combi.

I know. The problem is that nothing OP does to his system will make that combi do what he wants. A good sized cylinder with a good supply (better than they have at the moment unfortunately) is surely the best way to achieve performance on two hot outlets simultaneously.

To fit an accumulator with its cost for the gain of 3 or 4 ltr./m of hot water performance is not worth it in my mind but it's not my money.

The only practical way I can see involves a cylinder.

 

[Dale Sanders]

Would that mean removing the the combi? I have already emailed the installer stating I am not happy. Just waiting a reply

 

[ShaunCorbs]

Would that mean removing the the combi? I have already emailed the installer stating I am not happy. Just waiting a reply

No you can fit a unvented cylinder on your combi but incoming flow and pressure is key

 

[Dale Sanders]

Ok. I have not even been given that option.
I will do whatever it takes but nobody is telling me a guarteed fix.
What do you mean about flow and pressure is key.

 

[ShaunCorbs]

Ok. I have not even been given that option.
I will do whatever it takes but nobody is telling me a guarteed fix.
What do you mean about flow and pressure is key.

For any system to work correctly over two outlets you need about 3 bar and 20lpm on your cold main

 

[Dale Sanders]

I feel like I'm going around in circles don't get me wrong I really appreciate all your help but I don't have 20lpm I have 14lpm mains in and I have 3 bar. What can i do to resolve my issue with lease hassle and expense. I cannot remove the combi as I'd prob have to take the engineer to court for that the happen. Cheers

 

[ShaunCorbs]

I feel like I'm going around in circles don't get me wrong I really appreciate all your help but I don't have 20lpm I have 14lpm mains in and I have 3 bar. What can i do to resolve my issue with lease hassle and expense. I cannot remove the combi as I'd prob have to take the engineer to court for that the happen. Cheers

If you only have 14lpm that's no good for an unvented or a combi esp if you want two outlets

If you want to increase your flow, note not really worth doing that on a combi as your stuck with x amount as there limited

Stuart Turner

But that system will only last around 10 minutes at full flow eg 15lpm etc

 

[Dale Sanders]

The only issue to flow time to fill the bath. If it fills the bath in the same time as my cylinder did I'm happy

 

[Frog67]

One sure way to remedy this problem...Alter the Combi to act as a system boiler and install open vented S plan system using cylinder and CWST.
The head of water from your CWST and Hot Water Cylinder will be equal and if the flow rates still are'nt good enough you could even install a shower pump.
As someone stated earlier in this post, Combi's are ok for small one bathroom properties but that is basically it.
I wonder how many people throughout the years have ripped out open vented systems only to regret it once they realise how much more restrictive pressurised systems can be.

 

[Chuck]

I wonder how many people throughout the years have ripped out open vented systems only to regret it once they realise how much more restrictive pressurised systems can be.

Pretty much everyone who's had it done I suspect...

 

[Dale Sanders]

So had another local plumber out and without turning on any taps he identified the issue straight away. There is a double check valve on the mains going into the boiler. He says that can restrict flow by a lot. Thoughts?

 

[ShaunCorbs]

Yep there's a couple of lpm why was it installed, doesn't need to be

Also needs a shock arrestor fitting at the boiler on the cold mains