Originally Posted by Uber (Post 1696078)

He's installing the bypass the old fasion way. We remove alot of gate valves and ball valves now and replace them with a auto bypass that works on pressure, they should be 22mm really so the flow rate will remain the same with the valve open thus lowering the temp on pump over run quicker..

It needs this to prevent the pump from pumping hot water nowhere.. Like has been said in theory all of your rads could have TRV's on and they could all shut down, if this happens then theres nowhere for the water to go. The bypass should be set to prevent it opening on normal operating temperatures, it should only open if the pressure increases i.e because the valves have shut.

Good boiler the Vaillant thats all we fit and have only had a hand full of problems on the thousands we fit.. 2 years warrenty too i think with yours, their customer service is very good!!!

Oh and make sure he balances the system too, i.e turning down the rads that get hottest first to throw some of that heat to the other buggers rads perhaps!!!

Hope im helping in some way!! :D

~Rich~

Originally Posted by TSM (Post 1696086)

Even though i had 7 TRVs to install, he recomended to only install them in the bedrooms (3) as the living room and everywhere never gets hot enough to need us to turn the temp down, i will need to change the rads soon anyway along with the hot water cylinder as its not foam insulated, just blanket.

Ile try and insist to him that he should put in a 22mm bypass and put the valve, otherwise ile have to do it myself.

Originally Posted by Uber (Post 1696094)

If only i was closer i'd come and do your rads, cylinder and bypass for you, tis a nice little job..

As for the TRV's he's talking poop, they shut down on air temp not water temp so even if you think the rads not very hot it could still be hot enough in the room for the TRV to shut down. Thats where the money saving comes in too your not heating any unwanted rooms. Plus if you have them on all you rads you can turn the TRV's down low in the rooms you don't use very much and up higher for the living room ect.. This helps to balance the system too keeping the rooms you want warm warmer than the ones you don't!! :D

Originally Posted by nakedblue650 (Post 1696156)

Auto hydraulic bypass required for 1) benefit of boiler & system 2) to comply with Building Regs Part 'L'.

As you have 18kw of available power it should be in 22mm.

Also you shouldn't have any rads on the primary circuit or acting as by pass (commonly mis-referred to as heat dump!).

Also if you have TRVs on all rads you obviously wouldnt have a room thermostat! Another fail! You need a room stat to comply with Building Regs again! So anyone who says otherwise is talking poop!

if you PM me I can e-mail a Part 'L' regs overview if you want it.

nb650

Originally Posted by Uber (Post 1696078)

He's installing the bypass the old fasion way. We remove alot of gate valves and ball valves now and replace them with a auto bypass that works on pressure, they should be 22mm really so the flow rate will remain the same with the valve open thus lowering the temp on pump over run quicker..

It needs this to prevent the pump from pumping hot water nowhere.. Like has been said in theory all of your rads could have TRV's on and they could all shut down, if this happens then theres nowhere for the water to go. The bypass should be set to prevent it opening on normal operating temperatures, it should only open if the pressure increases i.e because the valves have shut.

Good boiler the Vaillant thats all we fit and have only had a hand full of problems on the thousands we fit.. 2 years warrenty too i think with yours, their customer service is very good!!!

Oh and make sure he balances the system too, i.e turning down the rads that get hottest first to throw some of that heat to the other buggers rads perhaps!!!

Hope im helping in some way!! :D

~Rich~

Originally Posted by nakedblue650 (Post 1696156)

Auto hydraulic bypass required for 1) benefit of boiler & system 2) to comply with Building Regs Part 'L'.

As you have 18kw of available power it should be in 22mm.

Also you shouldn't have any rads on the primary circuit or acting as by pass (commonly mis-referred to as heat dump!).

Also if you have TRVs on all rads you obviously wouldnt have a room thermostat! Another fail! You need a room stat to comply with Building Regs again! So anyone who says otherwise is talking poop!

if you PM me I can e-mail a Part 'L' regs overview if you want it.

nb650

Originally Posted by gerbrox (Post 1696411)

If the guy is worth he weight in gold he'll balance the system correctly, i.e. measuring the flow and return with an infra red gun and balancing the temperature so that all rads are 82 / 71 (regulating at the lockshields). he'll probably just vent all the rads andensure there all heating and leave. Also gethimto flush the other rads out as they sound as though there blocked full of sh1te andalso get himto fire some inhibitor in as well.