Flushing the radiator of the stove: how to cope without a master

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

Do not rush to disassemble half of the car and replace the heater with a new one: the problem can be solved faster and cheaper.

What you need to know before flushing the stove radiator

Why is the stove radiator clogged?

A clogged radiator is one of the most common causes of poor performance in a passenger compartment heater. Most often this happens due to poor-quality coolant, mixing of two antifreezes of different composition, or the use of water.

All this leads to the formation of plaque on the walls from the inside. Dirt tightly clogs the already thin radiator tubes with swirlers, disrupting circulation, and there can be no question of any heating.

How to understand that the problem is a blockage

It is quite simple to check if the radiator of the stove is really clogged. You need to find two thin pipes that go into the passenger compartment through the bulkhead of the engine compartment, and feel them. If one of them is hot, and the second is barely warm or cold, then this is a blockage.

In some cases, cold air will blow from the heater, even if both pipes are hot. This may indicate the following: everything inside is clogged so badly that the heated antifreeze enters the radiator tank and, bypassing the honeycomb, immediately leaves it, without having had time to give off heat.

What to do about it

The standard solution to this problem is to replace the radiator with a new one. This is what the car service will recommend. Here you have to fork out, because the cost of work is added to the price of a new radiator, and this is 2-3 times more expensive than the spare part itself. In modern cars, getting to the radiator is very difficult: you need to remove the trim and dashboard, unscrew the air conditioner tubes, and then refuel it.

The second option is rinsing directly on the machine. In this case, everything is much simpler and you don't need to shoot anything. It is enough to disconnect the pipes leading to the heater, connect a pump with hoses instead of them and run the flushing solution through the radiator.

How effective is flushing the stove radiator

Cleaning the radiator is much easier, faster and definitely cheaper than replacing, but this procedure has its drawbacks. Flushing is not a panacea, the chances of success are about 50 to 50. In advanced cases, sometimes there is no effect.

Again, on older cars, the radiator can only leak because the deposits that covered the holes in the pipes are washed away. Well, there is always the possibility of repeated ingress of dirt from the cooling system into the washed stove.

And yet, before changing a radiator, many car owners prefer to flush it first.

How to flush a stove radiator without removing it

1. Prepare everything you need

Almost everything you need for cleaning can be found in any garage, or bought in the nearest auto and home store.

• 150-200 g of citric acid;
• a bucket for 8-10 liters;
• capacity for draining antifreeze;
• hose about 3 m long;
• clamps;
• wires;
• mesh, gauze or nylon;
• water;
• antifreeze for topping up;
• transfer pump;
• boiler or stove;
• spanners;
• screwdrivers.

2. Understand the essence of the process

The principle of flushing the stove radiator is as follows. The heater is disconnected from the cooling system and a pump with hoses is connected to it. In a separate container, chemistry is dissolved and heated, and then, with the help of a pump, the flushing liquid circulates through the radiator. This dissolves and flushes out any accumulated dirt.

To prevent debris from getting inside again, it is collected at the exit and removed using an impromptu filter made of gauze or old nylon tights. Then the radiator is rinsed with clean water and the standard cooling system hoses are installed in place.

3. Remove the terminals from the battery

When removing the radiator pipes, you may have to disconnect several wiring connectors. Therefore, in order to avoid errors in the control system, it is better to de-energize the on-board network by removing the terminals from the battery. First negative, then positive.

Make sure that the heater is set to maximum heating beforehand. If control is carried out using a valve, then in the closed position it will block the flow of liquid and interfere with flushing.

4. Drain the coolant

The heater is filled with antifreeze. To prevent the liquid from leaking onto the floor, when you remove the pipes, it must be drained into a previously prepared container through the plug on the main radiator.

Since the stove is not the lowest point of the system, not all of the antifreeze can be drained, but only part. With due care, this can be done directly through the pipes during removal.

5. Remove the pipes from the heater radiator

Find and disconnect the two thin tubes that go into the passenger compartment. They are located between the engine and the bulkhead of the engine compartment. Usually they are easy to find, but if you can't or are afraid to make a mistake, check the documentation for the car or look on the Internet.

Then simply loosen the clamping clamps and remove the tubes by rotating from side to side. Be prepared for some more coolant to leak out.

6. Connect hoses and pump

Take any hoses of a suitable diameter (usually with a diameter of 16 or 18 mm), put them on the heater pipes and secure with clamps. Connect the free end of one of the hoses to the pump, wrap the other with gauze and lower it into the rinsing container. Also slide a small piece of fluid hose onto the pump.

You should get something like the one in the photo. As a pump, it is most convenient to use an additional heater pump from the Gazelle, which is sold cheaply in any car shop. Other options include a circulation pump from a boiler or a summer cottage pump for irrigation.

7. Prepare and preheat the flush

For cleaning from dirt and scale, specialized products are used, reagents for cleaning the sewage system, caustic soda and ordinary citric acid. The latter is the safest and at the same time no less effective.

Take 5-6 liters of water and add 150-200 g of ordinary citric acid, stir well and warm the solution. You can heat using a boiler, on an electric stove or from a gas burner. For maximum effect, the water temperature should be at least 75 ° C, and preferably close to boiling.

8. Start the pump

Fill the pump inlet hose with solution, quickly dip the tube into the container and turn on the pump by applying power. After that, the flushing process will begin: the liquid will circulate, draining into the bucket and again flowing from it into the radiator.

If the heater is clogged too much, water will initially flow out of it in a weak stream. Then, as the solution is exposed, the head will increase.

A complete flush takes from one to several hours, depending on the condition of the radiator. If the contamination is strong, then you may have to change the solution to fresh.

The main thing is to change the direction of circulation every 15–20 minutes by rearranging the hoses on the pump. This will help wash out as much dirt as possible.

When relatively clean water flows out of the radiator with a good flow, the flushing can be considered complete.

9. Flush the radiator with water

At the end of the process, it is necessary to wash off the remaining citric acid so that it does not later mix with the coolant in the system.

To do this, it is enough to drive a few liters of distilled water through the radiator. Drain the remaining solution, rinse the container, and then fill with water and start the pump as in the previous step.

10. Fill in antifreeze

After all manipulations with a jet of air, remove the remaining water from the radiator and disconnect the flushing hoses. Install the standard ones in their place and fix with clamps.

Check everything again and make sure the plugs are closed. Next, fill in the antifreeze that was previously drained, and, if necessary, add a new one - so that the level in the expansion tank is correct.

11. Remove air plugs

When removing pipes and flushing, air pockets inevitably form in the cooling system. Over time, they will come out on their own, but because of them, the heater may work intermittently, so it is better to get rid of the air right away.

To do this, you need to drive onto an overpass or a steep hill in order to raise the car's radiator as high as possible, and press the gas well several times. At this moment, gurgling will be heard inside the heater, which will stop after the traffic jams come out.

12. Check heater operation

Warm up the engine well and evaluate the result. If the problem really was in a clogged radiator and you did everything right, the effect will be pleasantly surprised. The stove will warm up like new, while the heat from the air ducts will begin to flow within a couple of minutes after starting the engine.