Home heating issue - Upstairs and downstairs

[Vik123]

Hi
I have a recent issue in that I can only get heat upstairs or downstairs but not to both. And when I do put just the downstairs heating on, the two furthest away radiators struggle to warm up even when the other radiators downstairs are turned down. Also, when the hot water comes on both upstairs and downstairs can't heat.

I have tried balancing and cleaning the system (cleaned all downstairs radiators via a hose outside and put in Fernox F3 cleaner) but that hasn't worked. I have also opened up the pump (Grundfos Alpha2 15-60 130) and ensured that it was spinning freely, which it was.

Two plumbers have come to inspect it - the first cleaned a few parts in the boiler along with suggesting putting in the cleaner to get rid of sludge as they thought the boiler and pump were working ok.

The second plumber suggested a stronger cleaner be used i.e. Fernox F5.

The system has a Spirotech MB3 fitted on the outflow from the boiler and before the pump - I know it is in the wrong place! Having figured out what it was, I cleaned it for the first time having to poke a cotton bud up through the hole to make the water flow out as it was so clogged up! It seems to be pulling black water every few days.

So, I am looking for suggestions on my next steps to resolve this heating issue. I have been thinking about the following options:

1. Just put Fernox F5 into the system and let it run for a week then drain.

2. Put Fernox F5 into the system and use a power flush machine.

3. Same as option 2 but use a magnacleanse machine to avoid extra pressure which might burst fragile pipes. This will be the most costly option as I will have to purchase the magnacleanse machine as I can't find any company that hires them out!

4. Replace the pump as even though it might be spinning freely, its strength may have diminished over time. I did notice that after agitating the pump the inflow pipes to the radiators downstairs did get hotter.

I am leaning towards Option 3 followed by Option 4 if Option 3 doesn't work.

Any advice is welcomed!

Thanks

Vik

 

[Aire]

Before this problem, how was your heating. Was everything warning up nicely from top to bottom? I'm thinking pump on this one.

What system is it?

I wouldn't recommend trying chemical after chemical though.

 

[Vik123]

The two radiators not heating up downstairs have always been an issue but they did get hot on occasions. The others downstairs were a little cooler nearer the bottom. That's why I took them off to clean them through with a hose. Upstairs has been fine.

But yes, we were getting heat upstairs and downstairs and didn't notice a fall off in heat when the hot water came on.

Now if both upstairs and downstairs are calling for heat, downstairs remains stone cold whereas upstairs is fine.

When I switch the pump (Grundfos Alpha 2 15-60 130) to Autoadapt mode it just stays at about 5 watts although I think it has always done this but I could be wrong! In any case, 5 watts isn't enough to heat the house so the Autoadapt isn't working as it should!

It's a gravity fed system.

 

[SimonG]

What size pipework feeds the radiators?

 

[Rob Foster]

The two radiators not heating up downstairs have always been an issue but they did get hot on occasions. The others downstairs were a little cooler nearer the bottom. That's why I took them off to clean them through with a hose. Upstairs has been fine.

But yes, we were getting heat upstairs and downstairs and didn't notice a fall off in heat when the hot water came on.

Now if both upstairs and downstairs are calling for heat, downstairs remains stone cold whereas upstairs is fine.

When I switch the pump (Grundfos Alpha 2 15-60 130) to Autoadapt mode it just stays at about 5 watts although I think it has always done this but I could be wrong! In any case, 5 watts isn't enough to heat the house so the Autoadapt isn't working as it should!

I think its amazing how well informed some if our respondents are now a days
it makes problems so much easy to look at
chking

 

[Vik123]

It has a circumference of 5cm which is a diameter of 1.59cm I think?

 

[SimonG]

I don't like them grundfos alpha pumps.

 

[Vik123]

What size pipework feeds the radiators?

It has a circumference of 5cm which is a diameter of 1.59cm I think?

 

[SimonG]

Aye 15mm which is good. But them alpha pumps can be too smart for their own good.

 

[Vik123]

Aye 15mm which is good. But them alpha pumps can be too smart for their own good.

So, you think the issue is the pump? What pump would you recommend for a 4 bedroom, two storey house with 17 radiators?

 

[SimonG]

I would use two. One for each zone.

 

[SJB060685]

Aye 15mm which is good. But them alpha pumps can be too smart for their own good.

Please correct me if I’m wrong but are we suggesting that the system is riddled with black iron oxide and this increase in pressure due to resistance is causing the pump to modulate, which in turn is not providing enough KPa to overcome and therefore not get heat everywhere?

 

[SimonG]

That's what I would be looking at.

 

[Harvest Fields]

You only need one thread about this issue.

 

[Vik123]

Please correct me if I’m wrong but are we suggesting that the system is riddled with black iron oxide and this increase in pressure due to resistance is causing the pump to modulate, which in turn is not providing enough KPa to overcome and therefore not get heat everywhere?

Probably! What's the best way to resolve the issue?

 

[Aire]

Have you or did the plumber remove the pump head and check the impeller was clean? I've seen loads of impellers and pump bodies that have been clogged up which obviously restricts the flow of water.

 

[SJB060685]

I’m reluctant to comment as I’m not an installer like SimonG and these other guys. I understand these things and how they work however I’m a humble hoover man (oil fired appliances). If the system IS infected with large amounts of sludge (black iron oxide) then a proper power flush is where I’d start, bare in mind this is not an hours job. The system should be flushed as a whole, then each rad individually and then the system as a whole again. Proper chemicals should be used and again larger systems could take considerably longer.

 

[Vik123]

Have you or did the plumber remove the pump head and check the impeller was clean? I've seen loads of impellers and pump bodies that have been clogged up which obviously restricts the flow of water.

I did the same as this guy:


Not sure if that's what you mean. The impeller was moving freely both ways and the water coming out was clear.

 

[Vik123]

I’m reluctant to comment as I’m not an installer like SimonG and these other guys. I understand these things and how they work however I’m a humble hoover man (oil fired appliances). If the system IS infected with large amounts of sludge (black iron oxide) then a proper power flush is where I’d start, bare in mind this is not an hours job. The system should be flushed as a whole, then each rad individually and then the system as a whole again. Proper chemicals should be used and again larger systems could take considerably longer.

Sounds sensible - I can hire a flush for the weekend.

 

[Aire]

I meant to physically remove the pump head from the body to expose the impeller.

 

[Vik123]

I meant to physically remove the pump head from the body to expose the impeller.

No-one has done that yet.

 

[SJB060685]

The pump acts as a magnet when rotating, any sludge and other crap in system will collect in the impeller. Observing this will show if pump is struggling

 

[Vik123]

Ok, i will try that before anything else then!

 

[Sharp Point]

Alpha 2 pumps are garbage, they look as if they’re working...but they hardly move the water, when faulty. Try another pump

 

[Vik123]

Alpha 2 pumps are garbage, they look as if they’re working...but they hardly move the water, when faulty. Try another pump

Thanks - what pump would you recommend?

 

[Vik123]

Pulled off the housing but can't pull off the actual impeller! Any suggestions?

 

[Vik123]

I managed to get to the impeller - all bar one of the channels for water were clogged up. Having unclogged these the pump is now running at 36watts vs a previous 25watts. When upstairs and downstairs and hot water are calling for heat, only upstairs and hot water are getting any. If it's just hot water and downstairs calling for heat, then it's just hot water which gets any. If it's just downstairs calling for heat, then it gets heat but those two furthest radiators are still an issue.

So, no change apart from the pump is now able to use more energy.

I am inclined to think that a power flush is the next step. Any thoughts?

 

[Vik123]

Is a power flush without a magnet much worse than with one? I can't seem to find anywhere that hires out power flush machines with a magnet!

 

[SJB060685]

A power flusher with a magnet collects sludge and stops what it can from being recirculated back into system. You want one really

 

[Harvest Fields]

A power flusher with a magnet collects sludge and stops what it can from being recirculated back into system. You want one really

Most of us add our own magnets to the power flush machine mate.

 

[SJB060685]

Yes I know adding your own strong magnet is just the same

 

[Vik123]

By any chance do you have a link to a suitable magnet, please?

 

[Harvest Fields]

Google magnacleanse

 

[Vik123]

Even though it won't be a power flush, would I be better off just buying a magnacleanse cleaning system like this:

Adey MagnaCleanse Complete Solution Kit MACK01 | City Plumbing Supplies

 

[SJB060685]

A permanent magnet should be installed on return back to boiler anyway to help. You would benefit from a proper power flush as well though as any hard set sludge in system may not budge and circulate back to magnet to extract. I once saw a system with V,C,P not right and all pipework was riddled with sludge, 22mm pipe had an internal bore of about 2-3mm it was that bad. In the end the guy said just rip out and start from fresh.