Hot water but no central heating after radiator install.

[billyboy123]

Hello,

I have a one pipe gravity fed open heating system with a potterton kingfisher MF boiler.

The radiator in the living was not attched to a bracket and was being held in place by a floorboard so I decieded to replace it.

I got a plumber to install the new radiator and install a drayton TRV4 valve and the pumbler couldn't get the heating to work after installing the new radiator.

The hot water works fine although when I first used the hot water after the install it has brown sediment in it but it runs clear now.

The heating system was working fine before and the radiators got to a good temperature.

The one pipe system has 2 loops for radiators 1 upstairs and 1 downstairs but neither are working, all radiators have been bled.

The heating pump is a comet 2-130 and runs really hot, I've tried all 3 settings but it still doesn't move any water through either of the radiator loops.

Anyone got any idea what it could be?

Thanks

 

[martygturner]

Air lock ? Crud lock ? diverter valve not opening, isolation valve not opened...

You need to work through the system. Bleed the rads and check that water comes out of each one, check the CH heating tank in the loft actualy has its inlet valve opened.... Has the bypass valve bee shut off.

 

[billyboy123]

I think crud lock is most likely since it's a reallly old system, is there any non-invasive way to tell if its any of those things?

 

[martygturner]

Drain the system... and refill a few times or get somebody in to do a system clean.

 

[billyboy123]

Thanks,

I've drained the system once and I'll do it again. When I drained the radiator in the living room it pulled warm water from the hot water tank through the downstairs loop. Could this mean it's a pump failure?

 

[martygturner]

Errr,,, if its pulling water from the hot tank why would it be the pump...and how would the hot tank be supplying hot water to rad as they are independent systems, the tank is only heated from the boiler via a heat exchange in the tank.

As I said check the diverter valve is working...

 

[SpecialK]

Isolate the pump and take the head off using the allen bolts. Does it spin when turned on and are all the flutes clear?

 

[billyboy123]

I took off the pump there was a bit of black crud, it spun when I tried to move it and I cleaned out the flutes. It's silent and I can't feel any vibrations when it's on settings 1 and 2 but it makes a hum when it's on setting 3. It's really really hot too.

 

[noddy997]

Is there Enough water in the system and all rads have water in them? Gravity fed systems can be a nightmare. 8mm pipework?

 

[mcmoby69]

I took off the pump there was a bit of black crud, it spun when I tried to move it and I cleaned out the flutes. It's silent and I can't feel any vibrations when it's on settings 1 and 2 but it makes a hum when it's on setting 3. It's really really hot too.

hum and really really hot usually means pump is stuck. try whacking it with a hammer on the pump body when a demand is put on it. might be new pump time

 

[billyboy123]

I drain down the system a few times as suggested and installed a new pump and fingers crossed the radiators are now working again. I'm going to install a magnetic filter add a system cleaner and then inhibitor. Thanks for the help.

 

[Johntheo5]

I drain down the system a few times as suggested and installed a new pump and fingers crossed the radiators are now working again. I'm going to install a magnetic filter add a system cleaner and then inhibitor. Thanks for the help.

What make/model of pump have (if) you installed and does it show the flowrate and power, what make/model was the old one??

 

[billyboy123]

New one is a DAB Evosta 3 and it can be set to show flow rate and watts, old one was an SMC comet 2-130.

 

[Johntheo5]

A good choice, a 6M?.
What setting is it on and what power (W) and flow (M3/hr) is it showing.

 

[billyboy123]

It's a DAB Evosta3 Circulating Pump 60/130 50-60Hz 220-240v.

Power is jumping around but averaging about 20w and flow rate 0.7-1.7 m3/hr when I've checked it.