Heating and hot water bypass valves?

[PDnsom]

Hi, first time poster so be gentle!
So I have just drained, gently flushed and refilled my heating system with no problems.
Looking at the installation which is a simple heat only boiler serving a pumped Y plan water and heating arrangement.
The heating system is conventional feed and expansion system, ie small tank in the loft.
All radiators bar one have thermostatic valves fitted - the remaining radiator is fitted with double lock shield valves which are permanently open.
The odd ball part of the system is TWO bypass loops (22mm and 15mm) fitted with gate valves between the boiler and the pump.
Given that the permanently open radiator provides any required bypass function does anyone have a clue why two bypass loops are
plumbed into this system?
All thoughts appreciated - thanks in advance

PDnsom

 

[ianmcd]

Welcom and I hope you find the site usefull, you would be better posting pics, your description doesnt really make sense

 

[PDnsom]

Hi Ian,

thanks for the reply.
I clearly made a descriptive error on my initial submission - the bypass loops (if that's what they are) are installed downstream of the pump and not between the boiler and the pump.
I've attached a couple of pictures as requested which show the layout in the airing cupboard; so heated water goes into the pump which is then directed to a mid position valve which directs water to the hot water tank or the heating system or both if in its mid position. The two 'bypass loops' were installed with the hand valves partially open which lets hot water recirculate back to the boiler (I believe).
I don't understand the need for the bypass loops given the heating system has one radiator permanently open at both its inlet and outlet positions. Seems like they are potentially not required and are just wasting gas by heating water that is recirculated back to the boiler?

 

[jeff the gasman]

Looks like a couple of towel rail connections to me!

 

[ianmcd]

As @jeff the gasman says, dont think it is a system by-pass , but some kind of manuall control for a bathroom circuit or towel rail or something

 

[PDnsom]

Hi Ian and Jeff,
thanks for your replies.
So there are no obvious take offs for heated towel rail (or similar) in any of the bathrooms or the utility room. I only have radiators in the main bathroom, en-suite and the utility room.
For context I bought the house from new 20 years ago with this installation in place as per the pictures and I haven't modified it in any way.
So if they are supplying hot water to something I've no idea what that might be.....

Thanks
PD

 

[ianmcd]

Hi Ian and Jeff,
thanks for your replies.
So there are no obvious take offs for heated towel rail (or similar) in any of the bathrooms or the utility room. I only have radiators in the main bathroom, en-suite and the utility room.
For context I bought the house from new 20 years ago with this installation in place as per the pictures and I haven't modified it in any way.
So if they are supplying hot water to something I've no idea what that might be.....

Thanks
PD

Only one way to find out, close tham and see if something stops heating up

 

[PDnsom]

Yes I guess so.
A simple short duration test shouldn't put any of the system at any great risk - I'll give it a go!

 

[ianmcd]

Yes I guess so.
A simple short duration test shouldn't put any of the system at any great risk - I'll give it a go!

you are not putting anything at risk, you already have a by-pass radiator

 

[Madrab]

Do the gate valves and the pipes they're on run hot when the system is on?

 

[PDnsom]

Hi Madrab
yes both pipes and valves run hot when the boiler is on....

 

[PDnsom]

Evening all respondents (Ian; Jeff; Madrab),

simple testing carried out and it appears the each of the two piping spurs feed a radiator in the main bathroom and the en-suite respectively.
Looks like the 'towel rail' observation was the correct call.
Still don't get why those two rads don't heat up when the call is for hot water only given that flow is definitely going out through those lines and the thermostatic control valves on them have been set to a mid position since the house was built - but that really isn't an issue.

So thanks to all for your comments and assistance - one satisfied DIYnot first timer

PD

 

[jeff the gasman]

Evening all respondents (Ian; Jeff; Madrab),

simple testing carried out and it appears the each of the two piping spurs feed a radiator in the main bathroom and the en-suite respectively.
Looks like the 'towel rail' observation was the correct call.
Still don't get why those two rads don't heat up when the call is for hot water only given that flow is definitely going out through those lines and the thermostatic control valves on them have been set to a mid position since the house was built - but that really isn't an issue.

So thanks to all for your comments and assistance - one satisfied DIYnot first timer

PD

They’ll only come on with a demand from the cylinder thermostat. Saving you money when on hot water only.

 

[PDnsom]

OK - got it

Thanks Jeff

 

[Madrab]

Cant see how that would the case though, given they are after the pump but prior to the 3 port ... that should mean they should be supplied by hot water with any call for heat.