Single pipe system blocked ?

[coey58]

If all was working well once, it is now almost certainly a balancing issue.

As I understand it a balancing issue is where individual rads take lions share of hotter feed , normally at the start of the loop , leaving other rads further downstream to be fed with cooler water. Surely if this was the issue at least 1 rad would be excessively hot and this is not the case.

 

[Ben-gee]

Or on a one pipe too much heat goes straight back to boiler - think of the boiler as being your ‘one excessively hot radiator’.

 

[coey58]

Or on a one pipe too much heat goes straight back to boiler - think of the boiler as being your ‘one excessively hot radiator’.

Wouldn't this only be an issue if rads had flow restrictions through them ?

 

[Gasmk1]

You possibly have a one pipe system relies on gravity normally to heat up each rad that why they are top entry bottom exit if your TRV’s are not full flow there is one restriction, you have probably messed with the lock shields so system is out of balance, what pump speed have you set it at it may be going too fast to allow flow into the radiators.

 

[coey58]

You possibly have a one pipe system relies on gravity normally to heat up each rad that why they are top entry bottom exit if your TRV’s are not full flow there is one restriction, you have probably messed with the lock shields so system is out of balance, what pump speed have you set it at it may be going too fast to allow flow into the radiators.

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[coey58]

all the rads are and always have been bottom entry and exit as diagram 2. My understanding is the flow thru rads is driven by combination of convection and differential pressure as whenever a flow is present in a pipe the pressure down stream will always be lower. I stand to be corrected but it would seem balancing the system is just about getting even / efficient heat distribution from each rad in the system.

 

[Ben-gee]

You’re clearly the man for the job, I expect you’ve fixed it by now.

 

[coey58]

You’re clearly the man for the job, I expect you’ve fixed it by now.

if it had been my house i'd have probably f****d it up altogether by now ha ha. As it's my mother's i'll leave it to the professionals , mind you i have now supplied them with job methods from sentinel and fernox for chemical clean and will be in attendance to make sure it's followed.

 

[Chuck]

I haven't read the entire thread in forensic detail but I can't see the part where you checked and ruled out the boiler heat exchanger. That's where the narrowest channels in the system are likely to be found. Is there a filter? If so, how much crud was in it. If not, that may be your problem.

 

[coey58]

I haven't read the entire thread in forensic detail but I can't see the part where you checked and ruled out the boiler heat exchanger. That's where the narrowest channels in the system are likely to be found. Is there a filter? If so, how much crud was in it. If not, that may be your problem.

no filter at the moment , will get 1 fitted if / when replace all pipework , eng coming back 19/2 to carry out repeat chemical clean so will ask him about exchanger then.