Advice needed new double rad and pump issue?

[SDBradfo]

Hi all,

I have had two roads replaced today in my home.

i have a gravity fed system with an Ideal a Classic NF30.

my house is very small and only had two rads and a towel rail.

one rad was replaced from a single to a double. The plumber had a lot of issue trying to heat this rad up, it’s the furthest from the pump in the airing cupboard.

hes recommended I look to get a combo boiler as he thinks the pump isn’t good enough to push water through the rad. He did get some warmth when he “blew” air through it from upstairs.

is there any point even looking at replacing just the pump? We have a Grundos UPS 15/50. Our three port valve would need replacing too.

thanks for any help and advice

 

[Aquarius]

Two rads and a towel rail, pump should be ample. What size is the pipework?

 

[SDBradfo]

Two rads and a towel rail, pump should be ample. What size is the pipework?

15mm I believe.

the plumber tried for ages but just couldn’t get it to work, only lukewarm when he “blew” through it but not sure what that means.

what I find odd is that the pipes to the rad don’t even get hot at all? Even following it all the way up to the ceiling.

 

[ShaunCorbs]

I would suspect an air lock

 

[SDBradfo]

I would suspect an air lock

Is that something for another plumber? Or possibly something I can do?
Another issue is my just over a year old motorised valve is just too so that would need replacing (potentially with the pump) and I’d still be left with a 25 year old boiler

 

[Aquarius]

As Shaun says, probably an air lock. If the pipes aren’t hot I’d just be inclined to check the flow from the pump and motorised valve.

 

[SDBradfo]

As Shaun says, probably an air lock. If the pipes aren’t hot I’d just be inclined to check the flow from the pump and motorised valve.

thanks for the reply.

the pump and valve (while broken) seems to be flowing ok.

the towel rail and bedroom rad are getting very hot (located on the first floor same as the pump)

move just took the head off the TRV and the pin went in and out ok.

I would have thought given that gravity is helping the flow pipe into the rad, that would at least get warm even if it didn’t have enough pressure to push water through the rad?

 

[SimonG]

Was the 'plumber' a plumber or an odd job man/handyman?

 

[SDBradfo]

Was the 'plumber' a plumber or an odd job man/handyman?

Definitely a qualified plumber.

I actually have some heat now. I turned the rads upstairs off and turned the pump speed from to 3 and it seems to be pushing water through into the rad now.

only thing I find odd is that the hot pipe feeds into the lock shield and not the TRV like I thought they should be

 

[exedon2]

Most TRV's are bi directional so should work either way
Sounds like your downstairs rad is drop pipe which can air lock but turning up pump and turning off other rads is standard stuff which any half decent plumber should have known.