CH pump sizing

[dhardy]

I have a long standing problem with inadequate flow to radiators. Despite all my efforts at balancing them only about half of them can be fed at the same time, while the others remain cold. I've tried flushing the system, and in some cases removing rads and hosing them through, but can't find any sludge build up. I'm wondering if the pump is under-specified (Wilo 60 Gold) and it's getting noisy, so I am considering replacing it.

House is a conventional 5 bedroom (large). Open vented system with 20 rads, all double panel, boiler is 45kW. What would be a suitable pump for such an installation? Would a meatier pump with greater head (Wilo is 6m) help or cause other problems?

 

[Terry lambert]

Sounds like a bigger pump could be the ticket, have a look at a 25 1-8

What boiler is it ? Could be pipe sizing is an issue, has it got separation like a low loss header

 

[Terry lambert]

Has it previously worked well ?

 

[dhardy]

It's a Firebird Olympic. No low loss header. The plumbing is conventional domestic.
And it's always been a problem since I've owned the house (10 years) although it seems to be getting worse (may be the pump performance is dropping?)

 

[Terry lambert]

I’ll have s look at the manual later, can you post some pics of wge4 your pump, valves etc are, I want to see how it’s set up

 

[dhardy]

Pics attached...

20180105_191148

• dhardy
• 5 Jan 2018

20180105_191601

• dhardy
• 5 Jan 2018

20180105_191258

• dhardy
• 5 Jan 2018

 

[Terry lambert]

I would most definitely be trying a bigger pump, check for pumping over etc in your F & E after fitting it, it sounds from your description of your system that this boiler is massively oversized

I couldn’t find a manual